jeffs 89 cutlass salon

I am in the process of removing the 3.73 ring and pinion out of my 7.5 posi rear.

they are Richmond gears. I would love to trade them for a set of 3.23,or 3.42's

they have only 600 miles on them. what should I ask for them?

dar83501

Not very much, I think, but I'm not an expert on the subject. The other day in the paper there was a GM 12 bolt 1/2 ton Chevy rear diff with 3.73 gears for $75.00, and that was the whole differential, not just the ring & pinion, and truck gears are generally stronger than car gears. That's my understanding anyway, somebody else has got to know a lot more about it than I do. Why do you want the higher gears anyway?

jeffs 89 cutlass salon

I want the 3.23, or 3.42's, as the 3.73's I have now, are not very highway friendly

dar83501

Ahhhh, this your daily?

My Cutlass is getting 4.10 or 4.11 gears, and they're going to be extremely highway friendly. Although, the Idaho State Patrol will probably heartily disagree.

jeffs 89 cutlass salon

well, it's mainly a weekend cruiser, maybe a few weeknights.

I was concerned that 3.73's and 14" tires would result in engine RPM's being too high at highway speeds

dar83501

I'm going to have a rev limiter on mine so I don't worry about that, but yeah, I see your point. It would probably ruin your day to throw a rod on the highway.

jeffs 89 cutlass salon

yeah, that's why I'm taking the 3.73's out

jeffs 89 cutlass salon

wonder if 2.73's would work well with a very healthy big block and 14" tires?????

The_Jeremiah

you might have a lot of trouble around town, isnt that about what they put in the assend of cars with the 2speed powerglides ? but yea your original idea of 3.23's would probably work fine

jeffs 89 cutlass salon

yeah, that's what I was afraid of
I'll have my 3.73 ring and pinion ready for trade/sale tomorrow

monzaz

With any v8 any gear will be fine. 14" tires are smaller diameter usually so a 2 series gear will be fine . they will definetely not feel like the 3.73 off the line BUT you will really be able to drive the car anywhere with out all the rpm noise level . Gear choice is really what you the customer want your car to do. All around performance is usually high 2's and low 3's on the gears with 2-3 speed tranny over drive and 4-5-6 speed trannies work better with mid to high 3 series gears.

NOW I do not know what all your motor and tranny specs are so this is very general. Jim

jeffs 89 cutlass salon

engine is a 430 Buick, aluminum heads, mild cam (.515 in,.515 exh lift,.284/.284 adv duration, @.050 duration:.232/.232).
trans, is a TCI street fighter TH 400, w/2600 stall convertor. My goal with this project, to make it a fun cruiser, with an occasional stoplight launch now and then

so, I could go ahead and run the 2.73's in the posi?? those 2.73's with the old v6 had a real good launch, might be fun with a very stout big block v8