More info as I've had guys tell me they couldn't find the part numbers I list on my site. After some digging the manufacture of those discs is Perfection Clutch (
http://www.perfectionclutch.com) Searching their parts catalog I found those numbers (
http://www.perfectionclutch.com/PDF/PC-404-Catalog.pdf) Since the specs aren't listed there and that catalog hasn't been updated in a while I went ahead and called their tech line to double check that these are the right parts and get the actual specs. He confirmed: RCF4190 = 9 1/8th" and 14/1 spline and RCF4201 = 9 11/16" 14/1 spline. I asked him about the length of the center hub on either side of the disc, he said there really is no way to know as he's seen them both the same as well as one side shorter like the ones I have. He said grinding it down some on the back side shouldn't effect balance very much so that would be fine if you don't have long enough splines or you could lengthen the splines on the input shaft.
Their site shows they are available from Advanced Auto but he said they prob. do not stock it so you'd have to order it in.
I also found them on Summit's site under the Zoom name (Zoom is owned by Perfection ie.. Same stuff)
http://www.summitracing.com/parts/ZZZ-RCF4190/ and
http://www.summitracing.com/parts/ZZZ-RCF4201/Hope that helps,
MONGO
