S4 vs S5 NA Clutch Difference
 

I think I will be in the market for a new clutch for my truck pretty quick. Looking at Rock Auto, they list 2 different part numbers for an Exedy clutch between S4 and S5, are there any differences? I would guess the S5 would be the better one.

I should add some details, I have a spec stage 2+ (I think, its the Kevlar one) clutch with a lightweight steel flywheel (10lbs lighter than stock), its in a B2200 with 4.78 rear gears, but I do use the truck as a truck. I occasionally pull a small trailer with a quad or a 10' long tent trailer (about 1500-2000lbs empty), and use the truck box, so this with the lightweight flywheel I think glazed it over by the extra clutch slipping needed to get a trailer moving.

Kevlar is intolerant to overheating and cannot recover.

Organic is the way to go.