427 tall deck???? I need HELP!!!

[1971 cheburban]

I've always wanted a 427, i now know where one is but it's the tall deck truck version, now everybody says that they aren't a good motor. But I would be building for the street not strip, what all would I have to do to make it street able. I know they came with the big 4 ring pistons. Can I do away with those and keep the original rodsa and crank, but have new pistons pressed on the rods? Everyone also says they don't like to rev, is it to much stroke or just the heavy rotating mass, maybe with lighter rods and pistons it would be better? Also the heads...... Are the original ones on it any good or just paper weights? Can I get any aftermarket heads and intake for it or no, I would be looking for a single four intake and I would use the original heads if they're good, I've heard someone makes an adaptor to use aftermarket intakes with the original heads or use aftermarket heads and intake?the originals maybe port them and have a valve job done, also exhaust..... Can I get headers or are the original manifolds pretty decent, and can I use a normal sized exhaust system. Also does anyone have the torque and horsepower numbers. Keep in mind that I would just be cruising the streets, maybe at a red light tach it to 3000 and sidestep it, just to melt some tires, but no strip runs, so no 7000 R's or anything like that. If anybody can help this 19 year old kid out I'd greatly appreciate it

[kwmech]

Save yourself a large headache and ditch the tall deck. Pick up a 454 block and a 396 crankshaft..get corresponding parts....put together.........there is your 427 done

[Fitz]

Originally Posted by kwmech

Save yourself a large headache and ditch the tall deck. Pick up a 454 block and a 396 crankshaft..get corresponding parts....put together.........there is your 427 done

Good advice. That truck motor uses truck heads and a boatload of other parts that you would have to change to get a decent street engine instead of a heavy lump good for a million miles at 35 mph. A 454 will be a bushel basket full of $20's cheaper and run much stronger.

Now that isn't to say tall deck motors can't make gobs of power. Both the ZZ502 and ZZ572 are tall deck blocks. But your tall deck 427 is not in that class.

[1971 cheburban]

Thanks guys, another question. Has anybody on this site put a tall deck 427 in a 67-72, I know the accessories drive is a little big, so I was wondering if it will fit? And what kind of motor mounts will I need? From our style trucks or from the big truck it's coming out of, also the bellhousing.... Is it the exact same as let's say a 6 cylinder bell? and will bolt to a an sm465/ m22 or the like? It has to have three pedals either way, should I just grab everything I can get my paws on from the big truck?

[airdale94]

They used to be desireable, not sure which crowd, but what they did, I think, was put standard deck heads on them. You have to use different push rods, not sure which, because of the deck heighth difference. Not sure what pistons. I thought about doing this at one time and looked into it. Search Google and I'm sure you'll find what your looking for. But yes if done right they are a awesome engine. And the wow factor is really up there. Economically you might be better off with a late gen 454. Got me curious again. I'll look into it and post anything I find interesting.

[MARKDTN]

Tall deck crankshaft is same as "regular" 396/427 and are made of the best material. I was pretty sure the stock heads were junk, but would interchange with regular BB heads. The big difference is the intake. You have to use a tall deck intake and your choices are pretty limited. There is a HEI for tall deck, so that is not too hard to get. Tall deck accessories are pretty bulky. All said, I would not go that way even if I had one. If you must have a big-block, get a standard height one.

I'm going to say it, LS has taken over big-block territory. Big block stuff is not bringing nearly what it did 15 years ago and LS is why. New C7 Corvette has 450HP and 450 ft-lbs torque and gets 29 MPG from a 6.2L (~378 cubic inch) LS based engine. You can't get 29 mpg from a 450HP 396/402/427/454/502 I don't care what you put it in. If I had a BB truck I wouldn't change it, but if I was starting from scratch, no way I build a BB.

[1971 cheburban]

We'll thanks guys for your input, the only reason I might do this is because I'll have a little funny money to play with and I know where a 427 is, and thanks guys for not being a-holes about this. I told some guy yesterday about my plan and he laughed in my face...... Thanks Airedale 94, if you would look for me I'd really appreciate

[MARKDTN]

I did a little more research to see if my memory was OK. I found this discussion.

http://www.jalopyjournal.com/forum/t...-block.773230/

This is a good discussion that hits the high points of swap and availability.

Summary-Looks like you can buy .4" longer rods and use standard pistons. They do have the good forged crank. Heads interchange. Pushrods (and distributor) are unique. Performance intakes are available now.

Still wouldn't do it, but parts are out there.

[airdale94]

Here's a couple.

http://www.hotrodders.com/forum/chea...ml#post1160950

http://forums.corvetteforum.com/c3-t...up-beware.html

Just punch 427 tall deck into Google in various combinations. Check out there torque numbers 500+ at 2000RPM!

Pretty sure the bell bolt patern will be standard Chevy BBC,SBC,I6. There all the same. Alot of those dumps come with a 5-speed stick. Might be neat.

[Bob B.]

You can't use regular BBC pistons in a tall block with standard rods. At TDC the pistons will be almost half an inch below the deck of the block, and you will have the world's lowest compression ratio! But, as other posters on this thread have pointed out, if you use the right parts you can build a nice tall deck 427. The question is how much will it cost vs. finding a old 454 and building that.

Yes, both tall block's have the same bell housing bolt pattern as a regular big block.

[1971 cheburban]

I was just going to ask if the bell is the same,the same guy has a muncie that's perfect...... He has both items so I'm thinking a combo deal, what you guys think? A 427 with the .400 longer rods and some nice aftermarket pistons, and the block bored to whatever size that makes it nice....i.e. .010 just to make it uniform, 4.250 is the bore, correct, so some nice flat tops. And get some big block heads, that guy has those also, and a dart intake and the distributor from summit that will for the tall deck, what kind of carberation should I go with? I really don't know, what feeds the big blocks best for street performance, Holley? And what kind of alternator, water pump and all that stuff do I need.... From the big truck or can I get some lighter stuff from summit? Thanks everybody for the inpuy

[1971 cheburban]

Mated to a muncie into a 3:73 posi 12 bolt, i think it will shred

[1972RedNeck]

Originally Posted by 1971 cheburban

Thanks guys, another question. Has anybody on this site put a tall deck 427 in a 67-72, I know the accessories drive is a little big, so I was wondering if it will fit? And what kind of motor mounts will I need? From our style trucks or from the big truck it's coming out of, also the bellhousing.... Is it the exact same as let's say a 6 cylinder bell? and will bolt to a an sm465/ m22 or the like? It has to have three pedals either way, should I just grab everything I can get my paws on from the big truck?

I had a 427 tall deck in a '72 K2500 w/ a 700R4 (I bought it that way). There was one reason I took it out: I couldn't get the A/C hooked up.

Actually I did have it hooked up using period correct p/s, alt, and A/C brackets. The problem was, I had to use the tall deck water pump. The block casting must have been different as when a short pickup water pump was bolted on, the water pump pulley grooves were pushed a half of a grove forward. A pulley with enough dish to offset this hit the casting. The tall deck pump must have been shorter than a short pickup pump.

Using the tall deck pump would have been fine and dandy but I couldn't hook the bottom hose up. I brazed a 2" 45* street "L" to the inlet and then screwed a 90* street "L" onto that. I got it hooked up fine but the hose was too short and it broke the radiator out.

On a side note, the factory bottom radiator hose would have worked great w/ just the 45* street "L" and solved all of my problems. I did not know this until I had the 383 sitting in the shop and just happened to hold the new hose up to engine before I took it out.

If you don't have A/C, the tall deck would be just fine. If you have A/C, I would think that having the block or water pump ports milled would work fine.

In other words, just get a 454 and be done with it.

Oh yes, there are spacers out there that allow you to run a short deck intake on a tall deck block.

[1972RedNeck]

Originally Posted by MARKDTN

Tall deck crankshaft is same as "regular" 396/427 and are made of the best material. I was pretty sure the stock heads were junk, but would interchange with regular BB heads. The big difference is the intake.

Three tall deck cranks I have seen were all forged - nice and shiny.

The one in my 427 GM Crate Engine (1990) was cast.

[rickpilgrim]

We have a 1972 tall deck 427 w/4L80E in our 1993 K3500 ex cab dually. Don't let people tell you they are slow to rev or can't hit 4000 rpm in a flash hasn't tried a good running one in a 1 ton or smaller car or truck.
Mine sits right on the 6.5TD mounts, 2 hits with the rubber hammer on the oil pan for front diff clearance and it dropped right in. The 4L80E shifts at 3750 but under full throttle I've seen 4000 before the computer catches up to shift. I used a 1982 454 water pump, used an aftermarket chrome BB Chevy alt mount and cut an extended it to work, used a March ps pump mount and an R4 AC compressor and brackets for a 454. Using the stock 427 lower pulley I ran all v-belts with a few shims to line it all up. I also used 454 exhaust manifolds and y pipe and a 3 1/2" single exhaust. On top I used a carb adapter to mate a Holley 650 spreadbore carb with the jets from the 427's Holley carb. For distributor I took a Chinese made HEI to the machine shop and paid $15 to cut it for the adjustable collar from the hardware store. To that I mated the 427's stock distributor gear and oil pump drive, had to file a bit of the bottom of the hei to fit the gear and dropped it in and set the length.
I had to add a cowl scoop to clear the 14x4 air filter and I use a carter electric fuel pump and 3/8" fuel line.
What I ended up with is a truck that when empty chirps the duals on the 1-2 and 2-3 shifts, revs faster than the optishift can shift for, make the 12v cummins and 6.0 power stroke guys scratch their heads and say wtf when we lose them on the on ramp with 7500 lb trailer behind, will tow that trailer at 80mph without straining, delivers 10-12 mpg when towing if you behave, has 10qts oil in it, never gets hot, never acts up, purrs like a kitten and handles that 24' ball hitch 15000gvw trailer with 6-48" and bigger zt mowers plus fuel cans and blowers/trimmers so well you forget it's behind you, especially in the city. You can easily make a 496 out of it, the intake manifold flows very good so just use exhaust adapters and keep the dual thermostat and you'll have a daily driver that won't disappoint .

[ihssalky]

I have a tall deck in my 70 c10. Works good. Its a bit crouded under hood but i have a dropmember and it moves things around. I started with tall deck block , stroker crank, longer rods, std pistons, and just about everything else is the same but intake and pushrods. Intake , i made my own out of a single plane. Shortened it and made a new flange. Intake spacers are avail but are a ***** to keep from leaking. Front drive is a little different with tall deck mounts but easily available. Trans mount the same. It is only a space issue and some parts

[1971 cheburban]

Man I'm learning a lot, what kind of pushrods do I need, can I buy them or do I have to have them made, and what good rods to use, I don't need the 800 for 8 expensive set but I want a good set, and the .400 longer ones too, also the distributor, can someone explain how that works, like if I was to use regular big block heads and intake, do I use a regular big block distributor? Or do I have lot have the adjustable one? Thanks everybody for your input

[1971 cheburban]

Also the factory oil pan, can I use it in one of our trucks or do I have to get another one? And 1972 redneck, did you use 67-72 big block mounts or the truck mounts?

[rickpilgrim]

I scrapped the stock 427 truck mounts and used the side mounts from the 6.5TD which are the same as any small/big block from 1973 on. I was able to use the big truck oil pan in the 88-98 4wd chassis, it's close, within an inch of the front diff, a bit more in front to the crossmember, plenty of room on the passenger side, starter bolts right up to the block. I had to run my tap through all the side mount/starter bolt holes-they were never used from 1972 to me. Everyone seems to hate the truck intake, I kept all of it, dual thermostats to 2" 90 bend hose, 2" to 1 3/4" exhaust adapter to 1993 454 stock hose on the upper, stock 454 water pump equals stock lower hose. Now that big water pump bypass hose under the thermostat housing I just bought 2 of those rubber frost plugs and a 2 1/2" carriage bolt.
Took them apart, re stacked 2 big washer, 2 rubber, 2 small washers put the bolt in stuck it in there and tightened. Not nice looking but very effective and has not moved in 2 yrs with my 22psi rad cap.

[Fitz]

Originally Posted by airdale94

Here's a couple.



http://forums.corvetteforum.com/c3-t...up-beware.html

Just punch 427 tall deck into Google in various combinations. Check out there torque numbers 500+ at 2000RPM!

Pretty sure the bell bolt patern will be standard Chevy BBC,SBC,I6. There all the same. Alot of those dumps come with a 5-speed stick. Might be neat.

Here's a link to a 427 build that took some time and started with a tall deck 427 block. Lots of time and lots of work to get it ALMOST done. It's worth following that link as it will give you some idea of what you need to know and what it will take to accomplish the transformation from a truck lump to a great performing engine. I would not try this build because here, in my home town, there is no engine machine shop that I would trust to do the work I would need to have done correctly and the nearest one that I would trust is 150 miles away. Then I've got to hunt for the parts...here's a list and their cost:

Heads (Ebay) 481.56
Block (Craigs List) 350
Machine Work (local) 592.78
Rotating Assembly (gofaststuff.com) 1800
Comp Cam XR276 HR (Ebay) 250
CompCams Hydraulic Lifters (Ebay) 300
Intake Manifold (Dart tall,single-plane) 410
Gaskets/Oil Pump setup (Summit) 150
Oil Pan 250
Balancer, cam button and plate 120.75
Summit (busted tool) 106.9
Summit (guideplates, keepers, retainers) 148.73
Valve springs (roller springs per CompCam Spec) 93.9
10-degree retainers and keepers 122
Intake pushrods (chromoly, Ebay) 21.94
roller rockers (Ebay) 142.9
exhaust pushrods (chromoly, Summit) 40.74
chrome valve/timing covers (summit) 35

Total 5,417.20 and it still is not in his corvette!


Total for a short deck crate 454 that would be a brand new drop in from summit:
Engine Assembly, Crate Engine, Chevy, 454 HO, 425 hp, Cast Iron Rectangle Port Heads, Each $5894.77

What's your time worth? You can spend weeks chasing parts, months uncovering problems and working out how to fix them or find another $477.57 (less than 10%) and get an engine that will start, has a warranty and back to driving that truck. Choices....give up 100 HP and 150 ft lbs of torque on a monster 427 build or get a 454 crate....Now that's a tough choice. I would be tempted to try that build if I didn't have to face the reality of doing some of the work twice or worse, chasing down a new block because the idiot at the machine shop ruined the one I sent him.

[1972RedNeck]

Originally Posted by 1971 cheburban

Also the factory oil pan, can I use it in one of our trucks or do I have to get another one? And 1972 redneck, did you use 67-72 big block mounts or the truck mounts?

It had the stock small block mounts as big blocks didn't come in 4X4's.

I think Dart makes an intake that allows you to use a short deck dizzy.

[1972RedNeck]

Originally Posted by Fitz

Here's a link to a 427 build that took some time and started with a tall deck 427 block. Lots of time and lots of work to get it ALMOST done. It's worth following that link as it will give you some idea of what you need to know and what it will take to accomplish the transformation from a truck lump to a great performing engine. I would not try this build because here, in my home town, there is no engine machine shop that I would trust to do the work I would need to have done correctly and the nearest one that I would trust is 150 miles away. Then I've got to hunt for the parts...here's a list and their cost:

Heads (Ebay) 481.56
Block (Craigs List) 350
Machine Work (local) 592.78
Rotating Assembly (gofaststuff.com) 1800
Comp Cam XR276 HR (Ebay) 250
CompCams Hydraulic Lifters (Ebay) 300
Intake Manifold (Dart tall,single-plane) 410
Gaskets/Oil Pump setup (Summit) 150
Oil Pan 250
Balancer, cam button and plate 120.75
Summit (busted tool) 106.9
Summit (guideplates, keepers, retainers) 148.73
Valve springs (roller springs per CompCam Spec) 93.9
10-degree retainers and keepers 122
Intake pushrods (chromoly, Ebay) 21.94
roller rockers (Ebay) 142.9
exhaust pushrods (chromoly, Summit) 40.74
chrome valve/timing covers (summit) 35

Total 5,417.20 and it still is not in his corvette!


Total for a short deck crate 454 that would be a brand new drop in from summit:
Engine Assembly, Crate Engine, Chevy, 454 HO, 425 hp, Cast Iron Rectangle Port Heads, Each $5894.77

What's your time worth? You can spend weeks chasing parts, months uncovering problems and working out how to fix them or find another $477.57 (less than 10%) and get an engine that will start, has a warranty and back to driving that truck. Choices....give up 100 HP and 150 ft lbs of torque on a monster 427 build or get a 454 crate....Now that's a tough choice. I would be tempted to try that build if I didn't have to face the reality of doing some of the work twice or worse, chasing down a new block because the idiot at the machine shop ruined the one I sent him.

I'd like to try one of these my self.

http://www.ebay.com/itm/COMPLETE-454...7c60fa&vxp=mtr

or

http://www.ebay.com/itm/COMPLETE-454...7c60fb&vxp=mtr

[MARKDTN]

Originally Posted by 1971 cheburban

Man I'm learning a lot, what kind of pushrods do I need, can I buy them or do I have to have them made, and what good rods to use, I don't need the 800 for 8 expensive set but I want a good set, and the .400 longer ones too, also the distributor, can someone explain how that works, like if I was to use regular big block heads and intake, do I use a regular big block distributor? Or do I have lot have the adjustable one? Thanks everybody for your input

If you use stock heads, you can use stock tall-deck pushrods.

Pretty sure you can use an HEI from a tall-deck. May want to change the curve and/or use a non-truck module. You can buy them with adjustable collar, but not sure it's worth the hassle.

The aftermarket intakes for tall-deck all appear to be single plane in Summit. The Corvette Forum article says the one he got was for the peanut-port tall deck heads. I don't put too much stock in that article because he never got it running. I am an Engineer. We do a lot of drawing parts and making 3D assemblies. In the real world, the fit is always close, but not always as nice as it looks on the computer. My point is that unless they finished the project, they don't KNOW that it will work well. The ones on here with running engines at least can say they have done it and can tell their experience.

It all still sounds expensive to me. I would take the crank and rods from the tall deck and go find a 454 block and build a regular deck 427 if I just had to have a big block. Or go buy a 502 crate motor. Or an LS.......

[67 cst swb]

I worked at a speed shop/machine shop back in Texas in early 1994.
We had a customer that went down this same road. He started with a tall deck block he got for free then used these high dollars 454 (std deck) pistons that he already had, then used an aftermarket stroked crank with aftermarket longer than stock rods and some aluminum aftermarket heads. Ended up with a 496cid that made really good horsepower numbers on the dyno.
But after he was done getting everything in the car and finished. He SWORE he would never build a tall deck motor again, ever... he said dollar for dollar he would of been better off buying a Dart big block bare block and using all standard deck big block stuff. He said it would of been way cheaper and way less headaches.

[Fitz]

Originally Posted by MARKDTN

I am an Engineer. We do a lot of drawing parts and making 3D assemblies. In the real world, the fit is always close, but not always as nice as it looks on the computer. My point is that unless they finished the project, they don't KNOW that it will work well. The ones on here with running engines at least can say they have done it and can tell their experience.

It all still sounds expensive to me. I would take the crank and rods from the tall deck and go find a 454 block and build a regular deck 427 if I just had to have a big block. Or go buy a 502 crate motor. Or an LS.......

Wow. I just got called out by an Engineer who draws parts and makes assemblies. Build lots of motors, do you? Probably not. I'm an engineer too, but I also build and race cars to keep me sane. Here's some pictures of my work. One is an LS3 powered spec Miata that I am building for the NASA circuit in Willcox Az, the other is a ZZ572 powered street/strip truck that makes it into the 10's at Southwestern International Dragway in Corona De Tucson. Where's yours? Let's see your work!