67-72 BigBlock 4x4s! Pos pics info here.

[6600DURAMAX]

I have the factory crossmember and there is no way I would have cleared the valve covers with the firewall without some "massagin" (beating with a hammer. I hate the idea also but it is not noticabel once the motor is installed. Not that that makes it an easy choice!!!

I did notch the frame rails so the headers had more clearance. The headers now slide in nicely from the top or bottom.

Belwo are some pics, in one of them you can see the notched frame. As you can tell from the pics BBC are a tight fit at the firewall. If I was to do it all over and had the time to mock everytihng up a couple times I would slide the motor forward about 1 1/2''. I would still have plenty of room between my pulleys and electric fans!

[hamllik]

I did one in my 1972 c10 4x4. I used the small block motor mounts the factory 1966 396 impalla valve covers with one of the sloped corners and a hei distributor. A short water pump and I had to hunt for a factory pan that would clear the cross member. The headmen headers for a 2 wheel drive fit except the pass side hangs too low to clear the front drive shaft. So I used factory manifolds. I cut the small block fan shroud down and it still works. With mine you can not use aftermarket valve covers. The only hacking I had to do was to trim the front cross member under the radiator a sliver abot a 1/2'' or so to clear the harmonic ballancer pulley that was it. My truck has factory air and I didnt have to mess with the heater box either. When I swapped in the 396 I also swapped to a 4 speed/np205 from a th350/np205. I hope this helps ya .

[Wildstreak]

I guess I didnt read the last post fully it explained my question lol

[Dieselwrencher]

Nice BBC installs guys!

[gmc 2500 4x4]

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[Todd Johnson]

I have two big block chevys (1968 2"s forward + 1970 stock location). If your going to make the swap it's easier to move the engine 2"s forward. You can install a 700R behind and the lengthen your transfer case shaft. The advantages are it's easier to reach transmission bolts, more room for valve covers, and HEI fits easier. Stock location on every truck will be a little different but you can put a 454 in the same place as your previous motor. Modifications are miner to make it work. The added weight will make the truck bounce more in front so I would suggest installing a rear gas tank to help balance the truck back out.

[gmc 2500 4x4]

is there an adapter plate used to mate a 402 to 350 bell housing?

[72chevyk10]

Originally Posted by gmc 2500 4x4

is there an adapter plate used to mate a 402 to 350 bell housing?

nope. chevys are all the same up till the ls engines

[gmc 2500 4x4]

good thread here, im gonna take the plunge and drop a 402 in my '69 gmc..sumthin bout a BB!

[waybad]

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[zeusflash]

Heres mine.....still needs work though!

[Rocketman72]

I installed a bbc in my 72 K5 about 12 years ago, left the cross member in the stock sbc location, I saw the extra holes in the frame and should have moved the cross member but I didn't. I was worried about what other mods I would have to do such as, shift linkage, drive shafts, transfer case mount hole, ect.

After reading this thread, I think I'm going to go with a 700R4 and move the engine forward. I can always lengthen the linkage and I think there's plenty of room for the 4wh shifter to move a little if necessary.

I used the stock bbc manifolds and some grinding was required and I also worked on the firewall behind the HEI dist. I wish I had not damaged my freshly painted firewall but, I did. I also had to do some work behind the valve covers also needed some clearance.

[Jsposito]

Great advice on this post. Should be very helpful. However, I see some of you are using the sbc mounts in the stock location and others are using the bbc mounts. I have both available. If I'm going to put the big block in the stock small block location what mounts should I go with?

[Rocketman72]

Originally Posted by Jsposito

Great advice on this post. Should be very helpful. However, I see some of you are using the sbc mounts in the stock location and others are using the bbc mounts. I have both available. If I'm going to put the big block in the stock small block location what mounts should I go with?

I think you can use the bb mounts by bolting them to your existing cross member. This should raise the engine slightly, increase your drive angle and make a little more room for your exhaust manifolds or headers if you should decide to use them.

If you are going into a K5 with your big block or if you don't have enough clearance I would suggest moving the cross member forward rather than beating up the firewall to make room. It's not very pretty after taking a sludge hammer to your firewall.

[Gobuffalo]

I guess I should pay attention to what I'm typing!
The right header comes out at a 45* angle. The left side points straight down. When I was done, I had I extra 90* bend and was short 1 45.

The big block stands won't bolt onto the factory small block 4x4 crossmember without modifying them.
I used all small block mounts and cross members to bolt my big block, TH400/NP205 in. I used the forward most mounting holes in the frame (I compared a 2 wheel drive, big block truck frame to mine). Even though I moved the engine forward to the factory big block position, I had to move the trans cross member back 1". Which means the t-case shifter didn't line up in the original hole, so it got a "custom" bend.

[Gobuffalo]

Right side.

[Gobuffalo]

Trans and t-case.

[71veronica]

[QUOTE=Gobuffalo;6779045]I guess I should pay attention to what I'm typing!
The right header comes out at a 45* angle. The left side points straight down. When I was done, I had I extra 90* bend and was short 1 45.

The big block stands won't bolt onto the factory small block 4x4 crossmember without modifying them.
I used all small block mounts and cross members to bolt my big block, TH400/NP205 in. I used the forward most mounting holes in the frame (I compared a 2 wheel drive, big block truck frame to mine). Even though I moved the engine forward to the factory big block position, I had to move the trans cross member back 1". Which means the t-case shifter didn't line up in the original hole, so it got a "custom" bend.[/QUOTE. Are you running a mechanical fan or electric?

[turp mcspray]

Since there never was a big block available in a 4x4, there is only the stock small block engine mount to use. The 2 wd mounts are completely different.

[Gobuffalo]

496, Edelbrock aluminum heads, Comp hydraulic roller cam, TH400, NP205, 14 bolt rear, Dana 60 front, 4.56s.
1970 Suburban. Got a long way to go.

[Gobuffalo]

Got some more done.
3" stainless exhaust, Magnaflow mufflers, new drive lines, new shocks.

[2 Far Gone]

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[CUSTOM/10]

Was that an exhaust kit, or did you just buy pipe, fittings and weld them up?
I'm planning on doing an exhaust on mine soon, very similar to yours but 2-1/2 in.

Gary

[Gobuffalo]

I used a Flowmaster 3", 409 stainless builders kit and Magnaflow 3", 409 stainless mufflers. The Flowmaster kit is about $350.00 from Summit. The hardest part was the flanges to bolt the exhaust to the headers. I could not find anything made of 409 stainless. I ended up using 3/8" steel flanges. You have to use a special welding rod called 309L to weld mild steel to 409 stainless.
I could not find any premade systems made of anything bigger than 2" for a 4x4. Lots of stuff for 2 wheel drive. The kit had almost enough parts for the complete system. I had to buy 1 extra 45* bend to finish the tail pipes.

[CUSTOM/10]

Your exhaust system looks & sounds like what I have planned on doing right down to the Magnaflow mufflers, with the exception of being 2-1/2 in. I have a 383 stroker built for more low end - mid range RPM. I have Headmen SS elite headers with 3" ball end flanges so I'll have to use a reducer.

Have you completed it yet ? Where did / are you ending it, in front of the tires, behind or out the back ?

Gary