Yes you can squeeze 3.54 or 3.75 gears in the Dana 36. I went from 2.59 to 3.54. You won't need a dragstrip to figure out how well they work. Just kick the throttle for the first time. It'll put a smile on your face for sure... Search this forum for Gears or 3.54 and look at my previous posts. It has all the info including part numbers for the conversion.
Other option is buy a rebuilt Dana 36 or completely convert to Dana 44. The rebuilt unit approach costs more. Swapping out to a Dana 44 will cost significantly more.
If you just wnat to haul a$$ from time to time then swapping gears in the Dana 36 is fine. If you're going to drag race a lot and push on it constantly then you may want to consider the Dana 44 approach. It will take more abuse. And higher HP if you are doing serious engine mods.
I would expect to pay about $1,000 before you're done. The gears I chose were from Strange. Richmond, Precision, Yukon and others are out there too.
I did the master rebuild kit. This contains all new parts that go around the gear set to get a good fit. Plus you need 3 new peices for the speedometer to work properly. Then after about 500-1,000mi you need to get the rear end drained and refilled.
That should cover it. I don't think I could have put a $1,000 into the car anywhere else and got that kind of improvement.
If you do mostly city driving then the 3.75 is fine. I do a lot of highway so I backed down to 3.54. My gas mileage has suffered about 1 to 1.5mpg on average. But it was worth it.
I just completed a swich from 2.59's to 3.75's this past weekend, and all I can say is WOW!!! That is one complimenting mod! I lost some top end but I really didn't need to go 160+ anyway, I now just get up there quicker.
I was browsing the 1990 specifications and under the rpo # there seems to be a 3.54 gear offered from Gm I wonder if you can still get the GM 3.54 gear set or possible find a whole rear end assembly at a Corvette salvage place. hmmmmm thinking!
You won't get that GM 3.54 gear set for the Dana 36 even if you can find it. It is out of production but there are some floating around. The cost I was quoted was a joke. And that gear is for a Dana 44 only. It was meant for the manual trans cars.
Once GM got the bright idea to go to 2.59 gears in the auto trans the only option was the G92, ie, 3.07 gears.
There are plenty of companies that have good quality gears. For the Dana 36 it is either 3.54 or 3.75. They are called Thick Gears for the Dana 36 that came with 2.59 gears. Make sure you are clear on that when you order the parts.
First time you hit it and see how the car jumps from 1st to 2nd gear you'll be saying the same thing Howser just said, WOW! That's what I said too.
Hey thanks alot ,why in the world would GM even offer 2.59 gears in a Corvette ? Even in my 94 Caprice with its dogg and I do say dogg 4.3 V8 (aka) baby LT1 it has 2.73 with a option of 3.23. Yeah I might Just look into trying to buy a complete dana 44 3.45 at a salvage yard. I have only one reputable drivetrain place where I live they wanted $700.00 to do my Caprice with 3.42 gears but that was with GM gears which is the only thing they will use grant it that is not a bad cost just thinking how much the Vette would cost if they would do it a since this is not a GM factory gear well you get the idea I'll keep ya posted.