Thread: Rear end swap question

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Hello all,
I am kinda new to the boards and i am trying to find a little help,
I have a 1985 chevy full size caprice coupe, I just dropped in a 383 stroker and a extreme duty 700r4, The stock rear is a 10 bolt 7.5 2.56 non locking rear, well needless to say i wanna swap to a posi unit, i was gonna just buy a eaton diff and stick it in the original rear, but now i been hearing that the 7.5 will not hold up to the torque of the 383, I was also told that a 8.5 10 bolt rear from a buick grand national will bolt right up, anybody know if this is true? i would think the GN rear would be more narrow than the caprice? or can anybody recommend what would be an easy swap that i can hunt down in the salvage yards?


Thanks in advance

Originally posted by Machu10
Hello all,
I am kinda new to the boards and i am trying to find a little help,
I have a 1985 chevy full size caprice coupe, I just dropped in a 383 stroker and a extreme duty 700r4, The stock rear is a 10 bolt 7.5 2.56 non locking rear, well needless to say i wanna swap to a posi unit, i was gonna just buy a eaton diff and stick it in the original rear, but now i been hearing that the 7.5 will not hold up to the torque of the 383, I was also told that a 8.5 10 bolt rear from a buick grand national will bolt right up, anybody know if this is true? i would think the GN rear would be more narrow than the caprice? or can anybody recommend what would be an easy swap that i can hunt down in the salvage yards?


Thanks in advance

Well I'm not sure about the swap but the 7.5 in my 98 camaro is still going stong. I do the 1/4 mile thing all summer with no probs. I have changed my gears though. To my knoledge a modified 7.5 is good till about 400 rear wheel hp. If the car hooks hard you could have some problems though.

The 9" Ford is going to be easiest to find & they are king of the hill. Lots of info on them on the web.