Technical Swapping rear gears - advice

I’m looking by to swap out my 4.11 for 3.55 in my 1950 Chevy styleline. Would anyone have a parts list for what is needed to do the swap?

thanks

 

We need more info.

 

Is it all essentially stock?

 

You didn't give enough info but what you gave leads me to believe it's the stock rear, probably a torque tube. I would bite the bullet and put a late model 10 bolt in and convert to an open drive. That's just a suggestion but that's what I would do.

Pat

 

Chevy's of the 40's

 

Yes, it’s a completely stock 50, standard trans. Just looking to get better cruise speed. I’m also swapping out the 216 for a 57 235ci at the same time.

I’m looking to keep the car build somewhat true to the era, otherwise, I’d go SBC, 200r4, and open/modern rear…

More so, do I just need a ring and pinion set or is there anything else I should purchase to do the gear swap?

thanks

 

If you're asking you've never set up gears before.

You'll want bearings because you'll want to make setup bearings which requires destroying one set of bearings. Whether you re-use the OEM ones and destroy the new ones or vise versa is up to you.

You'll also want seals because why wouldn't you put new seals in.

Obviously you'll need the proper measuring tools to set up gears and you'll want marking compound (thin it with a bit of gear oil, and only mark a few teeth, not the whole ring gear).

 

Grab the whole center section and torque tube from a 53/54 powerglide car

 

Yep, shouldn’t be to hard to locate a rear end from a “hot rodded” power glide car. A lot of people that modify cars have no use for the old parts.

 

My 53 was a factory power glide car. And thats exactly what happened to the stock stuff when I swapped rear ends lol. It and the factory power steering was put into a 53 hardtop in Texas for a teenage girl's first car

 

Add gear lube, expect possible brake parts (while you are in there), check e brake cables, rear brake hose and shocks before the job starts.
You are going to be touching a bunch of old parts. If it's been restored and in great shape, most will be able to be removed and replaced without incident. If it's a typical old car, there will be worn, rusty and just plain shot stuff and might have modified/patched stuff too.

 

I agree, the stock PG cars had 3.55 gear, and that would be a direct bolt in swap. You really only need the center section, but probably will find a whole rear as previously suggested where someone swapped to open drive rear. The non-OD cars had 3.70 gear, so that's not too much higher than 3.55. Better than a 4.11 gear which the OD cars typically had.

 

"Non-OD"? That would be all of them. Chevy never had overdrive until '55.

 

I would be on the lookout for vintage PG parts as said.
In the meantime, I would do the engine swap and drive the tires off of it.
Tall rear tires help a lot.

 

Thanks all. Sounds like it would be best to find a good PG donor rear.

 

I know a lot of guys cringe at FB but I often see drivetrains and parts on marketplace from power glide cars that the owners Boyd-a-lized cheap

 

Hello,

Having a 58 Impala with 4:11 gears, seemed to be the correct gear ratio set up for our 348 motor and transmission. It was a Positraction unit and it worked well for all around cruising and drag racing. Then the top racers had one advantage over everyone else. They put in a 4:56 Positraction unit from the factory offerings. Now, that was a performing rear set of gears.

But, like all things, we also cruised on open highways and freeways with the 4:11/4:56 combinations. The power was there when we wanted it and we moved at a slower rate due to the high revving motor. As our racing days were slowing down and there was no need to run the 4:56 gear or even the 4:11 gears on the street, there were times I kept the 4:56 gears and my friend in his powerful 57 Chevy bel air hardtop ran the 4:11 gears. We were not going to drive to San Francisco with those gears, so the local drive-in restaurant cruising scene was “geared” (pun intended) for simple cruising and the sometimes high speed action.
thanks, @themoose
When we did do more driving to the local mountains, the San Diego beaches and far inland locations for water skiing, the Impala was switched over to a 3:55 set of gears. The powerful motor was enough to still do the high speed runs, if needed. It was a little less faster than with the 4:56/4:11 combinations, but enough to win if needed.

The 3:55 gears in local driving down the coast to Laguna Beach on PCH also became more enjoyable. But, the thing we did was to have an extra third member already set up with the other “race” style of gearing, 4:11 unit and the 4:56 Positraction unit. So, we could switch it anytime, for any action necessary. The changing of the actual ring and pinion was not necessary as we just dis***embled everything and popped in the new set of gears as the situation required.

Jnaki

So, for your story and experience, there are complete rear ends available with 3:55 or other gears advertised everywhere, so start searching. Popping the complete units in and out, is a no brainer versus tearing apart your own gears for replacement. Plus, when you do put in the SBC power train as you find out the newish motor does not have the power you want, it is already to re-install quickly.

During the “Spring Break,” we put in the 4:56 Positraction gears, although the run down PCH to Laguna Beach, and Balboa Island was a high revving action. The gearing was set up for the encounters we were bound to have, heading into the teenage gatherings at Merle’s Drive-In Restaurant hang out and the local beach cruising locations. YRMV

 

You are right, I was thinking later years. The 49-54 car torque tube drive is quite limiting on ratios: three; and number of transmission gears: three. No four speeds.