I'm getting ready to build some Sportmaster shorties for my Formula. I can obviously go two different ways, I can use the parts out of my stock b1 cases or go the extra mile go with 1 1/4" prop shafts. My engines are only 450 hp so they are not going to be breaking anything. So drive guys, which is the wiser move? If any of you have some used XR shafts and carriers then I'm pretty sure I know which way I will go.

I really don't think it matters with HP, the props you have are they hubbed or solid B1s. so you could try they and get a base line. It wouldn't be a bad idea to have spare lowers

Just for the record... I managed to twist a standard bravo prop shaft with a 330 454. But then again, I am kinda hard on stuff...

My bravo's have the replaceable hub. I've not yet broken or twisted a prop shaft, but I have twisted an input shaft. I'm going to see if I can find a good deal on a set of used XR carriers and shafts. If I can I'll go that way.

If you decide to use XR prop shafts, you'll have to take about .060 off the prop shaft. The I.D. of the standard Bravo gear (just before the spline) is a bit smaller than the XR gear

Thanks- I am going to have the shafts turned so I can run standard gears.