The 7700 really isn't an ideal motor for a T4. Look at the 5700 or 4600, both will do quite well. If it were my car, the 5700 would be my choice (I do in fact run the 5700 in a 1/10 4wd buggy).
SH Z-Car, Custom Crawler, 8s Savage, 12s XTM XLB 1/7 buggy, 4wd 4-link rear/IFS Pro4 truck, Custom Hyper 10 Short Course, Belt-Drive Mammoth ST 1/8 truggy, 4s 17.5 MM Pro HPI Blitz