Why not beef up an eight inch rear? How much would it cost to add a posi unit and change gear ratio? i'm new to this and it seam so much trouble to use a 9/8.8 inch. Thanks for your help.
You can buy a center chunk with custom gears and trac loc for around $800.
They are good for 550 HP.
You should also change out the axle bearings and seals for another $100 in parts and labor
I took it to an offroad shop where they work on 4 wheel drives alot. Cost me $1100 for a 355 posi that has also been beat up alot.
I have a buddy thats had an 8inch rear in a strip car with drag slicks on it for 20 years, these things are pretty tough.
Oh, I just noticed your running a 5 speed, I`d go either 390 or 411 gear ratio with that tranny, if I could reverse mine and do it over, thats what I would do, the 355 I have is too low, I cant shift into 5th gear till about 70 mph.