My car stalled and had it towed to a shop. I have a 66 Chevelle 383 motor (425 hp) with a 350 Turbo trans, 10 bolt posi and spooled 373 gears. Man it was one heck of a job to push the vehicle in the shop's garage. It took four guys to finally push it in. The shop guy told me the reason why it's so hard to push is because it's has Posi and it's spooled, both tires lock and rotate at the same time. I didn't think about it much then until one day I release the parking brake on an incline and the car just stood there.

I am wondering if the Rear axle might be too tight? I thinking of changing the gear to a 4.11 anyway.

I can spin the tires and the car accelerates fine. Will take to track to see what it can do.