Are you referring to the crankshaft pulley bolts? I bought my underdrive pullies from MAC and they came with some allen screws for the crank pulley. I dont remember exactly how big they were, probably about 3/4" - 1" long. Just pull out and existing bolt if you need to get a rough estimate on the size and the thread pattern.
__________________ 2003 Saleen S/C Convertible #224
3" Pulley, JLT Cold Air Kit, 42# Injectors, Ford GT Fuel Pump, SCT Chip Custom Tuned by Pro-Dyno
90 GT Hatch - T-5: 70MM BBK Throttle Body and EGR Plate, MAC Fenderwell Cold Air, MAC Aluminum Underdrive Pulleys, Accel Adjustable Fuel Press Reg, FRPP 9MM Plug Wires, Accel Coil, PA Performance 130 AMP Alternator, Steeda Tri-Ax Shifter, Centerforce Dual Friction Clutch, FRPP Aluminum Driveshaft, Shorty Headers, O/R H-Pipe, Flowmaster 40's Dumped - Sold | 
underdrive pulley bolts , i need help 
