what gear to use with t-45rs transmission
 

going to use keisler t-45rs in a 1978 nova, has 330hp 350 ho with carb, will be running 245/60/15s, car has 2.73 in it right know,with first gear in it, having hard time to deside what gear to use ,thanks

I had a Tremec 3550 in my Mustang with the 3.27 low gear. I think you will have 3.35 low, so similar. I ran 3.55 gears with 255/45/17's on the back and my 1st gear was pretty steep. My car made around 375hp and when I stomped the throttle in low gear it was hard to shift into 2nd quick enough.

That being said it was nice in traffic etc., because I could just let the clutch out at idle and chug along.

3.55's worked pretty well for me though.

I'd put the transmission in and drive it before changing the rear gear ratio. You're going to be walking a line between first gear overall being too low (high numerical) and fifth gear overall being too high (low numercial). If fifth is too high, it becomes unusable because your engine may not run well under load at relatively low rpm (under 1,900 or so). If first is too low, you're at red line crossing an intersection.

As it is, your 2.73 and a T45RS first gear is the equivalent of a wide ratio Muncie and 3.55's in first, and fifth gear is the equivalent of a wide ratio Muncie and 1.84's (if there were such a ratio) in fifth. My guess is that you'll want to be in the 3.23:1 range.