62 stepside rear end

[62step]

Hey Guys, First post.
I have a 62 stepside that I am restoring, I got it from a friend who partially started restoring it. Frame sandblasted and paint, new brake lines fuel lines etc. was done. He did the 70's front end for 5 lug and rear he did 12 bolt 5 lug also. I am rebuilding this truck for a good cruiser, but I also want to be able to get on it when I hit the gas.. I'm putting a 350 motor bored .040 over with flat top pistons 041X heads and edelbrock performer intake, 274H comp cams, and probably 750 edelbrock carb.. For the trans I might go with a turbo 350.. I'm not too sure how to do a torque converter lock up switch for the 700r4's..

Back to my question..
I have 3.07 gears in the rear end now, will that be good enough gears to get up and go and do a couple burnouts in? It doesn't have posi either..

I was thinking about 3.73 maybe with the turbo 350 trans and posi. I would have to replace the whole carrier for that ratio correct?

Thanks in advance for the help and answers!

This forum is awesome.

Mike