I would like to go to a posi or limited slip for my 68 RS. It has a 327 with a t350 trans. 255/47/17 tires on rear (26.1dia) I was told with new axles gears and a good posi unit the 10 bolt would hold up on street tires.
Some day I would like to install a 350 or 383 crate motor lets say 400hp.
what gear would be best I do not drive freeways that much. And am I wasting money on my 10 bolt.

I built a 8.2 10 bolt for a '69 Camaro that held up behind a 383 with a 4 speed on street slicks for 6 years. It's still good, but not in the car anymore. A new Eaton posi and a 3.55 gear would be good for what you want. A good set of axles is recommended. I installed Moser axles in the 8.2 above.

26" tires and 3.55's is about 3000rpm @ 65ish
3.73's may be a bit much but everyones different.

See this site From what I see 3.73 with 26 inch tires @60mph=2958 and @ 70 mph =3451 ? what to do. thanks for the info keep them coming.
http://www.ringpinion.com/Calculators.aspx

26" tires and 3.55's is about 3000rpm @ 65ish
3.73's may be a bit much but everyones different.
I am going with the 3.55 thanks

See this site From what I see 3.73 with 26 inch tires @60mph=2958 and @ 70 mph =3451 ? what to do. thanks for the info keep them coming.
http://www.ringpinion.com/Calculators.aspx

Don't forget converter slip if its a non-lockup.
I see 3000 @ 65 on mine w/ 27.5" tires.

So what converter should I be using. 3.55 gear 26.1 dia tires th350 trans 327 with headers MSD box distributor Edelbrock carb. ? on the cam but its not stock. Camel back heads.(or hump?)

Run what you have and see if you like it before swapping. Your's may be fine as it's in your car now.

Run what you have and see if you like it before swapping. Your's may be fine as it's in your car now.

I plan on it. Yet I would like to know what others are using in similar cars.

(Maybe 2400 to 2800 stall)