8.75 or Ford 9”???

Most all 60’s slingshot dragsters had 8 3/4”.
Yep, and before the slipper clutch was devised to absorb power, keeping the 8 3/4 from breaking, they spun the tires for the whole quarter mile, keeping the 8 3/4 from breaking.
Edit: Look, i like the 8 3/4, i swapped one into my V8 vega many years ago, and i have one with a locker in my bracket 62, but i also have a dana and two nine inch fords. I have no problem with putting a dana in the o.p's possible thousand horse stickshift car, if he wants to keep it all mopar (even though dana was never part of chrysler corp, just a supplier). But he asked 8 3/4 versus a 9, and there is a thousand big power cars with nines for every one witha 8 3/4. There must be a reason.