373 gears?

I believe you can get 373's out of all MCSS's and 442's. The GN's had 342's. The gear selection really depends on the use of the car. If you are running interstate speeds at all, you may learn to hate the 373's w/o OD.

Yeah, you may want to consider something else if you don't have OD as I found out, I have a Chevy 350/350 combo with a MCSS rear w/3.73 gears and it tops out at around 63 mph, or at least that's as far as i'll push it. Hopefully sometime in the near future i'll be building a 200-4r with heavy duty parts and it'll make the 3.73's more livable.

I'm sure you could trade someone that B&M 350 for a OD transmission

I have 3.42 gears in my '84 MC SS without overdrive. At 60 MPH, the engine is turning over at about 3000RPM. The car is not my daily driver, so I'm OK with that. I wouldn't want a daily driver that runs like that. It would have to have OD. When the MC SS went to the 3.73 gears in '85, they also went to an overdrive transmission.

sickolds said:

is it that much of a difference right now ill do 70 at 2300 rpm :!:

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I have an 86 442 with the 3.73's and the 200-4R O/D trans. at 70 she turns roughly 2700 rpm.

Sickolds,

If you're doing 2300 at 70mph, then you probably have a 2.41 or 2.29 gear, more than likely the first one.

You can get a 3.73 rear end from either an 86-88 monte carlo ss, which the housing is a 7.625 rear end, or a 442 which uses an 8.5 inch rear end.

My old setup is a 350 with a 350 trans and a 2000 stall. My car came with a 2.29 gear and I've run both 2.41's and 3.73's. I currently have an 86' monte ss rear end rebuilt with yukon 3.73 gears. The original pinion chipped a tooth two months after I put in the rear end.

With 15 inch z28 wheels and a fairly low pro tire, I was turning 4000 rpm at 70-75 mph. With 20 inch irocs, that will help keep the rpms a little bit lower than what I posted, right around 3600-3800 rpm. But since your sticking with a TH350 and it's a daily driver, along with your 20 inch irocs, I would definately suggest finding a rear end with or swapping in 3.42 gears.

The 83-85 monte carlo ss's, t-types, and grand nationals came with 3.42's. Not all of them are limited slip so make sure you check that before buying anything.


And just for the record, I'm now swapping in a 700r4 OD trans. I spent a lot of time on the highway and the high rpms really do limit your top speed and get annoying after a while.