Some answers: I shouldn't think one would need to get aftermarket con rods. The factory jobs look very substantial, especially for street use.
The pistons in the stroker kit are different! The pin is located up 1/8th inch closer to the flat portion of the piston top (it's called "compression height") since the stroke is 1/4 inch longer.
Sorry I can't answer the one about possible case clearance problem, though. If the case does need some grinding for clearance, what one should do is to get a 1/4 inch shank, 3 inch long 6 flute carbide cutter. (This type is for use on aluminum and plastic only!) Just chuck it up in a regular old drill and grind away. Be sure to use wax or WD-40 on the flutes to keep the aluminum from clogging the cutter flutes.
