Pinion size

A what power - weight level should you make the step to a 35 spline pinion gear?

1000 hp 3000 lb.

When it breaks its time to change lol.

When I broke my N case years ago I made the swap and its never been a worry.......

IMO your there.

So are we now saying size matters? lol

I think it can also depend on what gear ratio is used vs if the car needs the dead-hook, or needs the wheel speed at the launch.

I know around here a few of the lower-buck heavier blown Pro Mod guys are getting away with using the small pinion stuff because their high rpm combo needs a bunch of launch wheel speed to keep from falling on it's face. And since some of these guys are also gearing for the 1/8 mile they couldn't find an off the shelf big pinion if they need to run more than a 4.86 gear anyway.

But if you're dead-hooking a heavy torque monster with less than a 4.86 gear and don't have wheelie bars to help lessen the load on the pinion by generating some initial tire rotation/wheel speed, then getting a big pinion might be something to think about.

On a side note from what I have heard you can special order big pinion gears steeper than a 4.86 for the 9" from Mark Williams. He takes one of his Modular housing 11" gear sets & cuts it down to squeeze it into the 9" case.

We use small pinion street gears. 1500 plus horsepower 3300lbs.

I haven't measured it but it looks to b as big as the trans out put shaft

Doesn't hurt to go with the bigger stuff IMO, I have the big pinion stuff in my car, but I was starting new on everything when I built it.