The Stovebolt Site Forums The Shop Area Engine Shop 350 engine in my 51'

planning to drop a 350 with a th350 tranny in my 51 GMC longbed. Anyone see any issues to think about?

There are plenty, the first of which is it's a sin to put Chevy engines in GMCs.

But besides that you'll have issues with your steering box, among other things. This is a common swap and there has been plenty already posted about it.

I'll turn to reading the posts. Thanks for your response

"There are plenty, the first of which is it's a sin to put Chevy engines in GMCs."

Cletis, isn't that exactly what the factory does? When I went looking for a 350 Chevy engine core for my roadster project, one place that had some cores available was the local Pontiac-GMC truck dealer.

All you street rodders out there: The best source of 350 Chevy engine cores I found when I was looking for one was the Chevy and GMC dealers. Surprisingly, their price ($100) was a fraction of what private sellers were asking on Craigslist and in the local newspapar. I got one from a dealer who let me pull the pans to find a 4-bolt unit with a standard bore and a perfect looking crankshaft within factory specs. All he asked was that I put the pans back on the ones I rejected.

That is what they do now but contrary to popular belief, GMCs weren't "the same as Chevies" in the '50s.

I have not seen a TH350 installed without cutting the bellhousing cross-member out. I would not do this to my truck.

why not, cut it out and fab one to put a little further back wtbd?...

yar what do you mean call the dealer for a 350? they just happen to have a bunch sitting around?

That cross-member is tied into the front cab mount on the outside of the frame...

Cletis, to each their own. There just aren't a lot of original GMC engines out there. If my AD GMC 3/4 ton had an original motor, I'd have kept it that way. But it didn't. Saying it's a sin is addressing roughly half the AD-owners out there.
...Just sayin'.

Yar, that's a very good tip, thank you. I've been looking for a 350 engine core and didn't want to pay up to $1350, which I've actually been quoted from one salvage yard!

Turnintotruckin, I put a 350 engine in my AD truck, because at the time, my weaker-than-a-wet-noodle 235 CHEVY engine went bad and the 292 Stovebolt I had my eye on was sold the day before I came up with the money. Yes, the steering box is in the way. But I worked around it by spacing the box 1 inch outboard (it'll stretch), and turning a pair of block-hugger headers upside down. But the preferred method is to replace the steering box altogether.

Hey Turnintotrucking......it's your truck....do what you like !
There are some aftermarket suppliers out there for modified trans members & motor mounts. Do a search here on the steering issues - they have been discussed a lot.

thank you all for your replys. this website is priceless because of people like you. I will keep all posted. the only reason I was going with a 350/350 is I have one in my Nova that was coming out anyway. You see, I have 2 51' GMC 100's. One is a complete 3 window truck that I will restore with the original 216 that's in it. The other will be a resto mod 5 window that had no drive train in it. The frame is already modified and I actually have the transmission x member to install. As soon as I figure out how to post pics, I will have plenty of stuff to show you.

Barry

It is your truck do what you WANT to do. I am doing about the same with a sbc350 and t-400 trans. Yes there some steering box issues and drivetrain that you will have to overcome. There is a group of purest that think any mods are a sin but I wanted to enjoy driving my truck not stuck in the garage fiddeling around with it to keep it running imho

Silverado_9c3, Chevy and GMC truck dealers install "rebuilt" engines for their customers. The old engine that comes out is called a "core". The dealer must either return the "core" or pay a "core charge", usually $100.

They are glad to sell you the "core" for the "core charge". It costs them nothing and you now have something to rebuild.

Many people believe that a "core" that has been through 1000's of heating and cooling cycles is completely dimensionally stabilized and superior to a "green" casting.

mustache man, doing an engine/trans swap is not a lifetime commitment. I was a 20 year old college kid when I got my '36 Chevy pickup in 1965. I swapped in a Chevy V8, B & M Hydrostick and 58 chevy pickup rear end and drove it like that for about 50,000 trouble free miles. Then in the early 70s I decided to restore it to all original condition and that was a total success. The 35 year old restoration still looks very presentable and we enjoy the '36 almost as much as our street roadster.
Bottom line, enjoy it-it's yours!

yar I know what a core is but a 350 has not been in a production model chevrolet for years now, I would venture to say all that are out there are out of factory warranty

They still sell 350 Goodwrench engines and some dealers charge a core charge on them. The one I bought from didn't.

Take a look at the crate 350s. I put one into my 58,runs great. I think this is cheaper than rebuilding a core engine and you have a new motor and 100k warranty.

hanksrags, from where I sit it's a huge leap of faith to use an engine assembled by someone else. Was he hung over that day? Did he use a $14.95 timing set or a Cloyes "True Roller" timing set? Did he use cheesy cast pistons or good hypereutetic pistons? Did he check all the clearances? Did he degree the cam in? Did he stagger the ring gaps properly? Was it honed with a torque plate? Is the rotating assembly balanced? Etc, etc, etc.

wow paranoid much yar? hahaha

Same problem with every new car. The motor has a 100k/3year warranty. I appreciate your comments, and would be concerned if this was a race motor. Just a stock driver.

Silverado_9c3, I guess you could say, "not entirely confident in others", "paranoid" seems like overstatement to me. How well to do any job, and in fact whether to do it at all or to farm it out, is an entirely personal decision.

I discovered as a teenager, about 50 years ago, that my standards are higer than most other people's standards. Even as a kid, I saw 2 options; lower my standards or do important tasks myself.

Asembling an engine is an example. Using a quality timing set that will stay tight means it won't wear out quickly retarding the camshaft which reduces low RPM power and requires constant ignition timing adjustment. To me, it's a real pain to replace a timing set with the engine in the car and I'll gladly spend some extra money on a quality Cloyes "True roller" set to avoid that miserable job.

Honing with a torque plate means the rings will have a truly round bore to seat against and be able to seal much more effectively yielding less oil consumption and better compression. I have a very high mileage rebuild on the engine in my '71 Dodge van that I bought new and it still uses almost no oil.

Balancing the rotating assembly means on the rare occasion when I feel like revving it up and feeling the secondaries open while merging with freeway traffic it will have the smoothness of an electric motor.

Using brass freeze plugs instead of cheap steel ones means I won't ever have to replace a freeze plug in that engine. My restored '36 Chevy pickup still has the brass freeze plugs I put in almost 40 years ago.

Etc.

Is it worth the effort? To me it's well worth it on many levels. To others it may be a complete waste of time and money. Both opinions are perfectly OK in my book.