Inliners International Forums General Discussion Drive Train To swap or not to swap

That is the question.

Hi guys. Just dropped in.

I have a 1948 Chev Aerosedan Im bring back from the dead.

Right now it has the stock 3 speed and closed rearend. Pushing it along is a sweet 62 235.

I need to get it up to freeway speeds. Im 50 miles from anywhere. So I have to drive a long ways just to go to car events.

I almost bought a 72 Pontiac Ventura II as a doner. The 250 was in fair condition, and it was backed by a slush bucket two speed automatic and
what ever rearend they put in those. I could also use the fornt clip.

My question is. Im not a fan of the 2 speed auto, I dont this this current setup would give me any more top end speed, than what I have not.

The ideal thing I need is a GM 3 speed/OD that I could mate to the 235, then use the 72 rearend and front clip, but trying to find one of those is near impossible without spending big dough.
I can get this 72 Pontiac for $200.

Will that 2 speed OR a turbo 350 bolt to my 235?

My other option is to sell my 235 and use the newer 250. Which Ill still need to bolt a turbo 350 to.

Need some ideas.

Thanks for your help.

Any transmission you get will be a 1:1 top gear ratio unless you get an overdrive. So if you put alot of work into it, unless you put in an overdrive- or make it into a pseudo OD using small rear-end gears, then you'll still be back at square one.
I can say that in terms of automatics, the Powerglide uses the least hp to run, but I don't recommend that for your intentions of driving mostly highway.....or the fun factor.

I don't know what to tell you otherwise.

Brad is correct.

On a 48 Chevrolet you'll need to change everything from the engine back and this is a major job and expense.

What you have is a good combination and the car is worth more money/easyer to sell "as-is" than afterward, as a general rule.

Good luck.

Eric,

If you don't have a lot of mountains to climb, you could go with a newer transmission from the '62 era 235 and go with a higher speed rear end, like a 2.73 or 3.00. Your engine speed with go way down and your fuel mileage will do better, too.

Here's how I know: In the late '70s, I had a '50 Chevy coupe with a 216, 3 on the tree and whatever the standard rear gears were. At modern highway speeds the engine was wound tight and sounded like it was going to explode.

I bought a '60 Chevy 235 engine with the original 3-speed transmission and installed a Nova rear end from a V8 car, with 2.73 gears. I felt sure I'd need lower ratio gears, but decided to drive it like that for a while. I was so pleased with it, that I never changed the gears. The engine was relaxed at 65 mph and the mileage was better than the 216s ever was!

That's my experience...........

Looks like Ill pick up the donor car, and sell off my sweet 235 and all my 48 gear.

Have to look into an 200R4

Thanks for the relies

Dennis, I'm not sure he's specifically on a mountain, but we're definately surrounded by them here on the West coast, except on the beach that is, lol.

We have all kinds of terrain here.

A lot of hills, to climb.

Not sure how that car would do on the hills with a stock engine. I lived in a fairly flat area at the time and I was more than happy with my cruiser. When I retired I sold it, never having climbed anything more than the gentle hills of north central Kentucky and southern Indiana. I now live in hilly Pensylvania and have a Chevy/Mercruiser 4-banger engine/4spd/3.55:1 8" Ford rear end, in a Model A. I can climb any hill around here in high gear. However, I wish I had OD on long, level areas of the Interstate.

Have a 47 coupe with 3:55 torque tube out of a 53 powerglide equiped car, she runs fine and loves the hills. As mentioned, the problem with your car and mine is that you can't just swap the trans or rear, you need to gut the entire driveline to make any major changes like open driveline. The trans you have is also the rear motor mount, stock side mounts on your car are junk, you need some expert advise.
You should contact Buffalo Ent. right up there in your neighborhood, for how-to and he has a zillion great kits/ideas for all chevs of your vintage. He has trans adaptors motor mounts, everything you'll need to swap anything into your old Chev.

Dear Eric;

That's good advice from Jim!!

Steve @ Buffalo will help you through everything.

Here's the thing; What you talking about is a vast project, for an experienced person, with a big shop full of tools/equipment etc.

Don't get in "over your head".

Good luck.

I bought the 72 Nova, so I have complete 250 running gear.

SOmetime next winter, ill rip all the 48 out and start the transplanting.

I would swap in all the 250 running gear. Just get the driveshaft length adjusted to suit. You'll like the car better. And it is easier to swap transmissions and stuff. And you can get an adaptor to put the 235 valve cover on it and still have the vintage look.