Ok, so my rear end is shot, and acts like an open diff when underload even though it's a posi. It's a 2.77 right now I believe.

Anyways, this summer I get new gears and a new posi unit, what gears should I put in? This is NOT a daily car, currently has a 305, and next year is either getting a 350 or 383, it will remain a street car, will see little track use, and is mostly a street car/cruiser. Now I'm young and like speed as well.. And I'm honestly considering putting in 4.56's, because I don't really care if I can go on the highway really... I want to build a car that when some dork is bugging me, I can just hit the loud pedal for a second, obviously win, and drive normal again... So I think my goal is more of an 1/8 mile car.

Anyways what do you guys think? My uncle was telling me about his pontiac he had when he was a kid with 4.88's and a 350, and said by far it was the most fun to drive of all the cars he'd owned.

 

Your uncles car had a carb too. What induction do you plan on using? Carb? EFI? If you plan on using a TPI, or S/R, those gears would be a big mistake. If you plan on going with a M/R, then, maybe, 4.11s. For the TPI, or S/R, I would personally use a 3.42, or 3.73. A 4.56 or more, will have your RPMs way up, and would be great if the car is a dedicated drag car, and everything else, ( cam, converter, etc.) is speced accordingly.

 

A bit of info for you: 2:77 gear ratio is a BW 9-bolt rear and you are not going to find many parts to do what you want. Even with new 9-bolt gears you have a 2-series carrier and the ratios you want will not work. A little research will help with your project.

 

Ah, sorry, I thought the gear ratio was 2.77, is it 2.73 that came in the 10 bolts? I know I have a 10 bolt, as.. it has 10 bolts and drums! I won't go near a 9 bolt, parts are too expensive...

Anyways, the car at most will some day have about 300HP, I plan on putting in a 350 or 383 next year, so, would I be ok with maybe a set of 3.93s, and be able to still remain fuel injected? Well, hopefully TPI, because it won't be until down the road I will have money for something like a stealth ram etc.

 

Please check and see what you do have for a rear axle assy.
Now if it is a 10-bolt 2:73 ratio 2-series carrier, you can buy special gears made for it or a spacer (not my choice).
The 10-bolt will handle your Horsepower numbers as long as you don't do anything DUMB.