I have a 1978 delta 88 royale 5.7 350 with a new top.Needs a little bodywork,I wont to redo the whole car but I was told it would be less money if i built a chevy engine vs my olds.First what trans is in my car? what besides the mounts would I have to change to do this,and what trans would I need 4 a 350s.b engine?one more thing I know that a 400 is a heavy duty trans but in my car,what would be better a 350 or 400 trans either with ashift kit.

 

Word of advise just say, "I've seen the light and I'm going all olds the word chevy shall never be typed on my keyboard again"...trust me...

IMHO either trans is fine but if I had both to choose from I'd use the 400.

 

Yes, cheby engines are cheaper.

I would stick with the Olds, not enough difference in price to make it worth it when all's said and done IMO. Especially if you have to buy a cheby engine and transmission and all that goes with adapting it.

"Olds is Olds and cheby is cheby and never the twain shall meet."

 

The chubby motor might be a little less, but not worth the effort changing everything around in your car in my opinion. you'd need caprice/impala frame mounts. The starter wires and alternator would be on the wrong side.
Your transmission wouldn't bolt up to a chevy without a $70 conversion plate.
You can't use a th400 trans unless you get a new yoke on your driveshaft.

 

Don't buy a Chevy engine. It might be cheaper to do a SBC with 2 bolt mains but to get a strong enough engine to move your Olds you will have to get the 8 bolt main "race motor." These are pricey.

 

Look at total cost. If you are planning on buying a rebuilt long block, you will need new motor mounts, frame mounts, accessory brackets, hoses, trans (or adapter), fuel lines, starter wiring, starter, flexplate, water pump, distributor, intake, carb, valve covers, exhaust manifolds, and exhaust pipes. All of these parts are different between Chevy and Olds.

 

If your worried about money just go out and find a good running used OLDS engine. Im sure you could find a good engine 455 or 350 (68-72) and be real happy with it.

 

Go Olds!
And the TH350 would be fine in you application.

 

Every time it looks like we've finally put this subject to rest, along comes someone else with the same damn idiot question.

 

chubbies are easy to come by... what do you expect? we all know they are a dime a dosen, the uninitiated are trained to think they are the shiz, which they are...shiz

 

CLASSIC OLDSMOBILE.COM

Not OLDSMOBILE with a Chevy engine.com

We come to this web site because we love are OLDSMOBILES.

Rookie mistake we will forgive this time

 

Those chebby blocks stretch out from here to next week!!

 

x2

Joe is right. Unless you have a free donor Chevy laying around that can give you all the items listed above, it would be better to keep it Olds. A Chevy motor maybe cheaper to build, but all the other items you need to make this work will make it too expensive. Besides, an Olds 350 will give you many years of reliable and dependable service. (And probably leak less oil than a Chevy motor) Good luck with your decision.

 

Lee:

Most of these guys were better to you than the last guy that asked this question. Just put you a nice Olds 350 in there with a turbo 350 and you are done. I had a 78 Olds Delta with a 350 and it was probably the best car I ever owned. Loved that car. The turbo 350 actually uses a little less HP to turn than the T-400 so you will probably be better off. I think the T-350 has a lower first gear too.

 

Possibly because the 77-up cars sometimes came with "Type C" motors from the factory. Or, we just don't feel as strongly about these cars as we do about older Oldsmobiles. On the other hand, my 86 Caprice wagon came with an Olds motor from the factory.

2.52:1 for the TH350, 2.48:1 for the TH400. You'd be hard pressed to feel the difference.

 

Possibly because the 77-up cars sometimes came with "Type C" motors from the factory. Or, we just don't feel as strongly about these cars as we do about older Oldsmobiles. On the other hand, my 86 Caprice wagon came with an Olds motor from the factory.

My 78 Delta had the Olds 350. I remember taking the catalitic converter off. Chief Auto Parts (remember them) sold was was called a "test pipe" that was to be used to see if your catalitic converter was bad. They were not on the market long before the EPA got on their butts and they yanked them off the shelf. I used a tapered piece of wood to enlarge the gas tank opening so I could put leaded regular in it. Some of the youngsters on here don't even know what leaded gas was.

Thanks for clearing up the difference in the ratios Joe. No way anybody could feel that. Do you have any idea on the difference in what is required to turn the two transmissions?

 

Test pipes are readily available today, with the appropriate legal disclaimers. It's well documented that the TH400 has greater internal inertia, but I don't have specific HP loss numbers.

 

I know this in an old thread, but sometimes its good to revive them and keep them current for topic of discussion, or for others to find. So in the event someone else, member or not should find it, my opinion is here.
I have been all Small Block Chevy all my life pretty much. Last year I bought a cheap truck. Saved it from Pull A Part and paid the guy $200 for it. It was an original Olds Diesel 80 GMC. Had many problems with it of course converted it to Olds Gas 350. Now I have it and was going to put a SBC in it. I had mentioned on my truck forum I belong to, about changing the mounts, wiring harness to get the starter to the other side etc. A member told me, I ought to check into the specs on the Olds 350, that I may want to keep it. So he talked me into it. I decided to stay Olds 350 but I wanted a NON windowed main 350. I actually started doing research on 455's. I also have another truck that is 454 BBC. I will keep the 454 since it runs good and has no problems, but my other 2 trucks, they are both getting converted to Olds motors. Easily done by just getting Olds diesel engine motor pads. To me when you do the REAL MATH, It is NOT cheaper to build a Chevy. It is IF you have the engine and the heads you are going to use. Chevy has a million differant combos on heads for both SBS and BBC. Olds is so much easeir to know what you want, and its not near as hard to find. Example being, I bet I can buy a set of Olds C BBO heads for alot cheaper than I could say some 69 Vette BBC heads. And tell me that that 69 Vette head will out perform an Olds C head !!! Go ahead and try, you will not convince me. Look at Valve size and CC chamber. Look at the flow rates for what you get out of the Olds motors vs Chevy Motors. Hate to say it, I still love the Chevy's and always will, but I have been converted. I will pay a bit more for my rebuild kits but have much better luck finding the Olds good stuff, and not someone thinking its worth a million dollars because it came off a Vette or a Yenko Nova etc. You can also compare Rod and Main sizes and tell me BBC to BBO or SBC to SBO is stronger. The Olds is stronger. Sure you can buy a dish SBC piston cheap, but compare flat top to top or forged pistons to Olds. Its about the same, or very little more for what you get. You have to pay to have more done to Chevy to get it to perform equal to an Olds right out of the box. Just stay away from Mondello's who should be a Chevy guy with their expensive parts, (ie Vette Heads). This Olds stuff is not gold and it is out there. You just have to find it. Although the Olds stuff is not Gold, I think its just a well kept secret. So, let me suggest, do the REAL MATH on Olds vs Chevy, but keep it to yourself. hahahaha