Thread: best gear for th350

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I have 1990 pontiac trans am with 355, the engine produced 420hp at 6100rpm
and 425tq at 4200rpm. I bought th350 for my car and was wondering what rear end gear would be best for me and also would converter would be right? the car weights 3200lbs with me in it. the car will be driven in town 90% and raced at track 10%, fuel economy is not a concern. i'm just looking for gear that will run me down the 1320 quickly and a street friendly stall converter that will get me a good launch. any suggestions would be awesome.

a good gear for the street would be a 3.70-3.90try the gear first then try the stall.need more info, cam, intake, comp ratio.

If you supply your rear tire size, and the RPM you want to be running at the end of the quarter mile, could tell you the best gear ratio for the track....

My comp ratio is 9.5:1, the cam is 218/224. dual plane intake, 750 carb, the tire size is 28inches tall, id like to see about 6000rpm at the end of the quarter mile.

A good gear for a street tire is a 3.73. With a 700r4 it will give you a very low 1st gear. An 11" converter would be good but a 10" would be better but depending on build it could be a little loose-slippy. With a good trans cooler the 10" would get the car to jump on that cam. A racy 10" or smaller is too much for the cam you have.

With a 28" tire, optimum gear for the quarter would be about 4.25.... Might go to a taller tire, like a 30" tall slick, then keep the 28's for the street and run a 4.56. No way it would be a highway cruizer, but it sure would be fun on the street, and still make a good drag car. As for the converter, don't know, I run manual trannies.