I'm currently in the process of starting my trans/rear end swap in my 72 cutlass. It has a SB 350 in it running somewhere just under 300hp(haven't dynoed it just a guess). My question is what gearing would be good for the trans and rear end. It will just be a cruiser not looking to race it just want to be Able to have some fun on cruise nights. Gas mileage is also not a concern. Thanks any advice is wanted and appreciated.

 

All depends on what you want to do I suppose. I swapped my one wheel peel with a posi unit and geared it up from 2.73 to 3.08. I've also got a 350 with a TH350. Should give me a little more off the line and still keep some highway driveability.

 

What are you looking to do with this car? If it will see any strip time, you need to consider that. A final first gear ration of about 10:1 is optimum. To figure this out, you multiply the first gear ratio by you differential ratio. Are you going to run an overdrive transmission? If so then you can run a little shorter gear and still not be turning 4K at highway speed. If you have a 1:1 final trans ratio and are just street driving it, 3.42s are a good all around ratio. You also need to consider your cam specs. Just something to consider.

Tom

 

3.08 or 3.23 if you will do highway driving, a 3.42 would be nice if it is going to stay relatively local. In my experience & observation anything close to or over 3k @ 60 is traumatic for most anyone but the harder core.

Limited slip IMO is a must.

 

I really like my 3.42's but granted, I stay local most of the time. However I run 28" tall tires in the rear which helps. And yes, just under 3 grand. We are spoiled nowdays with the overdrives. Back in the day 3 grand was nothing with 3.42's or 3.90's. Then add 4.11's!

 

When I was young & "harder core" I loved my big block 70 SS w/ 4.56, very short tires & M22, before that my 65 442 w/ 4.11 & M20 was a hoot!

When We put 3.08 in the red car to replace the 2.78/2.56, my kid came home distressed after his first ride on the highway!!! Now that we installed the 200-4R that spins about 1700-1800 @ 70 he is lovin life. Definitely an OD era child.

Definitely personal preference.