The Stovebolt Site Forums The Shop Area Engine Shop GMC motor vs Chevrolet

50 GMC 100,motor's tired.Parts to o/h a 228,248,etc. are well over a grand while later 235 kits are under $400.The owner's not concerned with originality-he just wants a nice Sunday driver.I'm thinking of rebuilding a pressure-oiler 235 and swapping it in.According to the Search threads,fabricating a front motor mount spacer plate and a different exhaust header pipe are the only modifications necessary.Are there any other potential problems?

Yes. The GMC guys grilling you about putting a car motor in your truck.

Every time the owner opens his hood , he will be making excuses as to why that 235 is in there. Tell him his Sunday drives will be much nicer with the 228..

You want to replace the GMC motor with a what?!
:confused: :confused: :confused: :confused:

Weigh the 228 and the 235 both on a scale and then decide which casting will go another 51 years and which one won't.

In my experience the 228 is a much stouter motor. If ur friend plans to use the truck for any real work, hauling loads, or pulling stock trailers--certainly need to keep the 228. Moreover, if he will be driving the truck thru New England could be a problem with the purists. Otherwise the 235 would be fine--quieter too. If it were mine, I would keep the 228 if I possibly could--good motor--really surprised the price differential is as much as you say.

Replacing a truck engine with a passenger car engine? You better be thankful Proffit's off in Europe chasing tail. He'd hunt you down and run over you.

As for the swap, yes, it's about that simple. I can't answer about the bell housing. Flywheels are different. I would guess you'll need a 235 starter, flywheel, clutch and bell housing.

The 235 doesn't come close to the 228. 235 has less nickel in the casting and is nowhere near the 228 in durability. 235 is cheaper to build, but in the long run the customer should be happier with the 228. But, the customer does pay the bill.

Oakey Doakey GMC guys- First,the amount of power is not a concern.If he was worried 'bout that,I'd shoehorn a Rat in the '50.As to longevity,are you guys telling me a 235 won't live very long,especially with limited use? In the Search mode a fellow says it costs about $1800 to o/h a 228 and from what I've seen,he's pretty close.Don't misunderstand me folks,I respect your passion for originality,but my customer doesn't really care.If it runs good,I doubt he would feel any reason to make excuses to anybody-I know I wouldn't.Two more questions from a newbie-Who is Proffit and is a GMC really a Chevrolet with all the bolts tightened?

I know that regardless of the driver and owner, anytime that I see a AD GMC truck rolling along or parked I always want to see the engine under the hood. I get this sinking feeling everytime that I find out the "old" GMC engine has been swapped out for a "new" 235 chevy engine. Where do all these GMC engines end up?????????? I don't understand. GMC had full pressure oiling designed into their engines WAY before chevrolet(1939 for GMC and 1954 for chevrolet I believe) The GMC engines are not as plentiful as the 235's but that does not make the 235's any better. I agree with everybody else in that the GMC's are a stronger engine and will hold up better to loads and doing work. Any inline engine is going to cost money to overhaul and $1800 bucks is not really that much in older inline terms. I can say that it will be money well spent.

I you decide to got rid of the 228, put it in the swap meet for sale or trade and someone will take it. I just think it would be a shame to have it end up in the trash heap.....

Let me preface this by saying that I really like the 235. I'm building a '60 model now for my '54 Bel-Air.

The 235 is fairly simple to build and parts for the '55-'62 years are still plentiful. In our Pre-'55 Chevy vehicles, they are the only bolt-in option if you don't want to cut the frame.

1st answer: In this era, the GMC and Chevrolet engines are totally different design. Almost nothing will interchange, and internal construction is different.

The 235 has drawbacks in general, often not worth the work as a replacement for another make in the GM family. One is that most any buildable 235 core you find is going to require a complete rebuild. This will cost 1,000 in parts, easy. Head work alone can run 300-400 dollars for all new valves, springs, hardened seats, etc. My 235 with heavy performance mods will cost 4 grand total. And even then I'll only have 200 HP.

The head and main bolts are not available new. (Neither are GMC, but a 235 doesn't solve the problem) There are other bolts and pieces that require a donor motor if they are missing/damaged in the 235 to be built. I think the flywheels, clutches, motor mounts, engine size & weight are also different between GMC and Chevy.

The 235 has only 4 main bearings and a long stroke, so its RPM range is limited to short bursts of 4,000 RPM. Max cruising RPM is 3,200 RPM or so. It has no full-flow oil filter. 235s are also infamous for rear-main oil seal leaks. The 235 also had "tapered" main bearings, where each sucessive main journal is a larger outside diameter. #1 main is the smallest and #4 rear is the largest. It makes crank grinding and sizing more difficult for a shop thats used to post-'63 engines. Almost nobody can line-bore a 235 block because of this.

Stock 235s were good for 135 HP and 220 FT-Lbs of torque ('60 specs). I think the GMC motors made slightly more power stock.

Both the 228 GMC and 216-235-261 Chevy engine families are antique obsolete designs. If the owner wants a driver with a 6 cylinder, look into a more modern design. A '65-'74 250 or 292 are more modern design and will accept V8 style bellhousings and trannys.

Now having said that, will somebody remind me why we work on these 235s at all?

Good luck
chip

KenMT...Nobody is saying the 235 is no good--just that the original 228 is stronger. Used to be a guy on this board with a 235 who claimed had nearly 400K miles on it. 235 is a good engine. If as you say, this truck is transportation to Sunday school, a well built 235 should last forever.

Good advice to sell the 228 core in the Swapmeet.

Replacing a truck engine with a passenger car engine? You better be thankful Proffit's off in Europe chasing tail. He'd hunt you down and run over you.

Fred, being hunted down and run over wouldn't hurt that much. The real torture would come from listening to the " Long Motor Envy Speech " for the rest of your days on this earth..

As for the GMC being a Chevrolet with the bolts tightened, you can torque every bolt on a 235 to 500 ft/lbs and you still won't have a 228..

I have to agree with the others. The GMC has a higher nickel content block, longer block life along the lines of a caddy. Stronger mains, better rods and pistons. An engine that when cared for will go 200K miles with little problem. The 235 is a decent engine. Not made for heavy hauling, and will last 100K with good care. I built one for my 52 Chev pickup because it was readily available and a drop-in. I needed to get my truck running as soon as possible. when I do rebuild the truck, plans are for a 292.

I would recommend either building the 228 or putting a 250, which takes different mounts and will probably end up costing as much as the 228 rebuild. If the customer doesn't want to spend that much, sell him the 235.

In my opinion, the 228 rebuild will be the best engine for the money. And if he ever wants to sell the truck, having the 228 will make a huge difference in the selling price. Probably more than the cost difference of the rebuild.

If the customer doesn't really care what engine he has, then I think that you might want to open up your horizons and look at all the motors that are available.

Thank you...I think that's the nicest thing anyone's ever said!

Ur welcome .... I think. If offense was taken by my post none was intended. I have enjoyed ur website and admired your huckster. A 51 3/4 ton jimmi was the truck of my youth and provided the means to earn the money for college. 55.1 Chevy now--too old to work that hard but enjoy the GMCs which are rare and hard to find.

An interesting note from our friend and sponser, American Classic Truck Parts:
"Almost all Canadian built GMC pickups prior to 1953 used the Chevrolet 216 engine, not the 228 and 248 GMC type placed in U.S. trucks. The Canadian Chevrolet using the larger GMC 228 and 248 was the "Maple Leaf"!"

First of all,thanks to all that replied.I pulled the motor today and plan to tear it down this weekend.I'm leaning towards rebuilding the original motor after learning more about it from you folks.I thought the GMC motors were "splash" lubed like the early Chevrolets,until informed otherwise.After teardown,if it looks rebuildable,I'll have a few more questions for you all,but I will start a new post.Again,thanks.