The GRP made Ninja, Boss and Falcon engines all share the same rod.
The GRP Tuned line and it's follow ups (TQ, Tecnopower, G5) share the same rod aswell but it's not compatable with the older GRP engines (Ninja, Boss, Falcon). The crankpin of the older GRP engines is slightly smaller
Kyosho ST-RR Evo-ed // Sirio // Hitec // Sanwa
Kyosho MP9 TKI2 WC // Sirio // Savox // Sanwa