rear diff

can anyone tell me what type of diff is in my 86 transam?it originally came with a h.o.305,4-barrel with borg warner 5-speed.

a 26 spline 7.5.

While we're on this topic, I have an '89 Trans-Am originally equipped with a 5.7 350 automatic...any idea which diff. is in it? Thanks.

I would need to know the vin to tell for sure but I would bet on a 28 spline 7.625 (which they call a 7.5). 89 is the year they switched from 26 spline to 28 spline axles.

limited slip or no?

Do you leave dual tracks when you take off?. I would think that the 5.7 would have to come with a posi but I am not positive. Thats easy enough to figure out though. Either Power brake it and see if both spin or jack it up and put it in neutral and a healthy posi unit will cause the other wheel to spin when you spin one.

yea, I just didn't want to have to resort to that...plus the engine is still out of the car as I am rebuilding it and was just curious. Thanks for the spline info. though.

thanks for the reply.i recently built and installed a 383 stroker for this car ,im worried if my 10 bolt will hold up to the extra torque.im wanting to replace the rear gear with a 3.73 to make it a little more streetable.any comments or ideas is appreciated