Olds powered 72 GMC

[Glennerd]

You bet they were pin-ups! HA HA HA! Pushing freshlings in the strollers as well! Kinda like when a group of young male lions overthrow the dominant male of a pride. The new males killl all of the recent offspring in order to have thier blood line for the next generation. Then, and this is where I try and find the similarities, the lionesses go into heat and are all ready for some action from the new guys. When I fire up the truck, I'm kind of expecting a few strollers to be released down my hill before the pin-ups walk past. It felt good to get that off my chest.

[Glennerd]

My donor fender got a little straighter today and splashed with some primer and flat black paint for now. Lots of broken bolts to take out of the pass. fender now. ARRRGH!

[Glennerd]

Got the fenders on, for the most part. Should be able to get things to line up a bit better tomorrow.

[Glennerd]

A little progress today, but not much, as the fenders had to come off again to repair the last 3 bolts that were broken off inside. The hammer was required for the final fit but no need for anything to be removed for a while now. My grille will be seeing the hammer and dolly tonight and then some fresh paint and a polish.

[kelly cotter]

Hello i am wanting to put a 455 olds in my 67 short bed that is a three speed manual going to put a automatic short shaft tranny i am woundering about the motor mounts and the frame mounts whay do i need to do what do i need to make this happen thank you Kelly Cotter. kelly.cotter@duke-energy.com

[Glennerd]

This motor was already installed in the truck when I bought it. Some quick searching has an Oldsmobile diesel 350 ci being installed into 1978-80 Chevy and GMC light duty trucks. The mounts should be readily available at any parts store, but I'm not sure of thier compatibility in the 67-72 frame rails. I'm sure you could find an easy way to make them work from what I've heard. Hope that this helps you a bit.

[Glennerd]

A bit more done. Grill came out great. Headlights seem a bit deep, but I can pry the base's out a bit if I need to. Got a new bag of sand for the blaster, so hood hinges will be next.

[MADMIKE]

Originally Posted by kelly cotter

Hello i am wanting to put a 455 olds in my 67 short bed that is a three speed manual going to put a automatic short shaft tranny i am woundering about the motor mounts and the frame mounts whay do i need to do what do i need to make this happen thank you Kelly Cotter. kelly.cotter@duke-energy.com

The '70 Deltas used an engine mount that bolted to the cross member with a single stud like the '70 350 V8 P/U mount. But, I do not know if the spacing is the same and if it would allow you to use it as a simple drop-in bolt on.

Glennerd as a fellow SBO aficionado I would like to help point out a couple of things on your SBO.


Note the 3A on the head, that indicates the heads are from a '77-'80 350 Olds. Now if the block is also a 350 it will have 3A or 3B along with the casting number on the ridge of the block where the the oil pressure sender is screwed into. If there's a 4A or 4B, congratulations, its a 403. The casting number should confirm this. IIRC the last three digits of a 403 are 557265, and for a late 350, 557752, diesel 350 block is 7582 I can't recall if there is also a D or D3 on that pad. Also on the side of the block above the starter it will actually have '350' or '403'. Funky enough a block with '355' cast into the side is actually a 260. Diesels have D or DX, and the 80s 307 has '5L' for five litre.

When Pontiac took over casting for Olds in ~'76 there were a few changes done to Oldsmobile engines. The engines came with cast cranks, windowed main webs(gas), and only high performance vehicles, such as the TransAm(403), 4-4-2 and Hurst Olds came with harmonic balancers. The average car, be it a Cutlass, Park Avenue, etc, did not. Possibly engines used in HD applications.

If you do plan on revving this engine past 3K rpm for a bit, I would highly suggest replacing the counterweight balancer with a harmonic damper. You will need to replace the timing tab with the correct unit as well, luckily GM still sells both. The vehicles that came with the Oldsmobile engine in the late 70s usually came with tall gear ratios, even in the 80's 307 Olds powered cars with a 3spd AT came with 2.14:1-2.41:1 final drive. 4spd OD units came with 2.73-2.41:1 final drive. This kept the operating rpms fairly low usually below 3K rpm. Which used on these engines with the self dampening characteristics of the cast crank, no longer needed to have a dedicated harmonic balancer installed. Saving on cost.

The problem with revving the engine, or the cause of some of the more chatastrophic engine failures when using the late 70s blocks is due to a combination of issues. One the lack of a harmonic balancer, which can be easily rectified. Two the cast crank, as it turns it also twists but beyond a set point the twisting causes the crank to bend. Combined with the 25oz external balance, or imbalance, the couterweights add to this bending load. There is no easy way to prevent this. The crank bending pulls on the webs of the block, eventually causing the cracks and failure of the block. Harmonics are induced into the block that cannot be dampened. You can reduce a large portion of these bending loads by having the crank internally balanced to 0oz. Currently it is a 25oz external. Using a quality elastomer damper, such as the ATI unit, will aid in reducing crank harmonics.

Olds are known for pumping the sump dry. The head to block drain back has a bit of a step that needs to be ported out to allow free flow of oil back to the pan. This can be easily seen by removing the valve cover, and noting the 1/4" step transition. Mondello claimed that too much oil was fed to the valvetrain. He offered restrictors to prevent excess oil to the top end.

[Glennerd]

Thanks Micheal! Feel like I got me a good skoolin there. lol I have the 350 but have had no hopes for any real power from this engine. I want to run this motor and build an earlier engine for a future transplant. I think I'm catching a bit of an Olds bug now, so I owe it to myself to at least start with a good power maker next time around.

[MADMIKE]

Originally Posted by Glennerd

Thanks Micheal! Feel like I got me a good skoolin there. lol I have the 350 but have had no hopes for any real power from this engine. I want to run this motor and build an earlier engine for a future transplant. I think I'm catching a bit of an Olds bug now, so I owe it to myself to at least start with a good power maker next time around.

Rocket engines do get you hooked.
FWIW, some cheap upgrades, look to 80-84 307 Olds engines. These engines came with an AL 4V intake, some claim as good as a Performer intake. These are identified by the 'A4' raised casting in front of the first runner on the P side. Also the '5A' heads used on these earlier 307s have 67cc chambers, the valves are smaller, but can be upgraded larger valves. IIRC the 3A heads you have are 79cc chambers. The intake/exhaust ports are comparable in size.

Avoid the later '85-'90 roller block '7A' heads(not to be confused with coveted '72 350 '7a' heads) and 'A5' intake. These have a swirl port design that uses intake ports less than half the size of a typical SBO. Great for smooth economy performance in a 2.14:1 geared car, but that's about it.

FlowKooler uses AL GMB water pumps for their line of water pumps. FK installs a back plate to the impeller for improved flow. However these FK modified GMB pumps can be anywhere from $80-120 US. The GMB pumps can often be found for considerably less. Anywhere from as low as $25-60 US.

[domeier]

Glennerd: You are about a busy little beaver! I love this thread, because it's like watching one of those build-a-chopper-in-24 hours TV shows.

Do you ever sleep? Eat? Go to the crapper???

[Glennerd]

Ha ha! I take my diaper off at the end of the day, wrap it around my head and then I can't eat or sleep. Back to work I guess. lol

[gcburdic]

oh geez....the image of you with the diaper around your head is hilarious!!!

[Glennerd]

3.5 hrs. of scraping and sandblasting. Just covered in ruberized undercoating like everything else has been.

[Glennerd]

An artist friend of mine has offered to paint my hood emblems for me. This is just the first coat and shot with my crappy cell phone camera but way better than I could have hoped for already.

[dan42]

Nice work! So watcha got under the car cover in the garage?

[Glennerd]

My fauxmobile valve cover wire looms showed up yesterday, but the valve covers haven't yet. What's under the car cover you ask? How about a 67 2dr/ht with 67,000 original miles. 6cyl/2spd and zero rust, zero accidents (a few wiskey dimples). My stepfather owns it and I parked it 10 years ago exactly where she sits. As soon as the 72 is running, this thing will be under way. Almost all of the new parts have been purchased including: 330hp GM crate 350, 700r4 trans, iwe 355 posi w/4whl disc brakes and all new suspension bushings, coils and shocks. It won't get a full frame off as he is running out of years to enjoy it. It is in such incredible shape, that it won't require much effort for it to be a nice, driveable car. The car was purchased in 83 with 23,000 miles. The front and rear seats still had the plastic on them as well as some of the arm rests. There was a tear in the plastic seat cover on the drivers side front so we took it off due to a dirty spot forming.

[Glennerd]

A couple of earlier pics when I was pre-fitting some of the plumbing, before I tore the front end off. 5 out of the 6 (fender to cab) bolts were stripped or non existent. Much drilling and tapping. I can't get over how much "mo- betta" the doors close and latch now. Hood is on but needs some fitting.

[Glennerd]

Bumper is on but needs a washer or 2 to get the gap closer.

[Sillyoldman]

Originally Posted by Glennerd

My fauxmobile valve cover wire looms showed up yesterday, but the valve covers haven't yet. What's under the car cover you ask? How about a 67 2dr/ht with 67,000 original miles. 6cyl/2spd and zero rust, zero accidents (a few wiskey dimples). My stepfather owns it and I parked it 10 years ago exactly where she sits. As soon as the 72 is running, this thing will be under way. Almost all of the new parts have been purchased including: 330hp GM crate 350, 700r4 trans, iwe 355 posi w/4whl disc brakes and all new suspension bushings, coils and shocks. It won't get a full frame off as he is running out of years to enjoy it. It is in such incredible shape, that it won't require much effort for it to be a nice, driveable car. The car was purchased in 83 with 23,000 miles. The front and rear seats still had the plastic on them as well as some of the arm rests. There was a tear in the plastic seat cover on the drivers side front so we took it off due to a dirty spot forming.

Thats a cool car

[Glennerd]

I would like to replace my master cylinder and booster to a smaller diameter set-up. Are they all the same part for GM vehicles of these years as someone has said to me? I need to create a bit more room for my air intake tubes as well as remove a bit of the ugly from under the hood. I have front disks. Are the power steering pumps all the same for GM vehicles of these years as well?

[Glennerd]

Valve covers finally came today, yeah.... Just posting a pic of the before and will have an after in another hour or so. Wire looms are in the oven @ 200 while the gold paint bakes on, then the stickers and the final look. Something a bit sketchy about drilling holes in a brand new anything.

[Glennerd]

Got the valve covers finished, but I put one of the stickers on a tiny bit crooked. #$%@!!! but I'm pretty happy with the outcome anyhow.

[Glennerd]

Picked up a Hurst Pro-matic 2 truck shifter for $50 yesterday. It came with all of the brackets and cable. Trying to locate the plastic console and chrome dash is a bit tougher than I thought considering how many guys don't use them. $90 plus ship. from hurst for everything I need, but I'm hoping someone can dig one out of the garage that they have no use for. Gonna have to be extra kind for a while if I expect to have some luck. lol

[Glennerd]

Bought a 72 cab today for a $100. Needs some patching in the floor, rockers and cab mounts. Mine currently needs it all as well so I figured the price was right and I'm not in a hurry. Also an excellent drivers box side for a hun. I want to have it all ready for next year's swap. I made the guy throw in the hurst knob.