If you nwant a dropin 2wd NC2 type try: Cartrix CTX1174 Motor TX2 NC2 Style 18,600rpm to fit SCX chassis supplied with motor adaptors and pinion 9.50pounds from Sean
My personal choice for power though is:
CTX1173E Motor SH Pro 30,000rpm fits SCX chassis supplied with motor mount & magnet 13.00pounds from Sean.
The second is an FK-130 that is the same as the old Plafit Fox. It comes with a second traction magnet if you desire the added downforce.
Performance per pound spent is better than NC type from Ninco
Also consider:
Slotit SIMC05 V12/2 29.000 MOTOR + ADAPTOR FOR SCX In Stock 11.00 (an FC-130)
RP28197 RT-10 NC2 TYPE MOTOR FITS SCX CHASSIS 13.00 (exactly the same as NC2 with adaptor)(more expensive)
SC-07 MABUCHI TYPE MOTOR TO FIT FLY, NINCO, SCALEXTRIC, MRRC, PROSLOT @ 12V, 35,000rpm, 0.44amp, 190gr/cm, Size 25x20x15mm £6.95 (make your own adaptors)
Jimmy