Probably the MGT 8.0 engine. Don't know if it's much better or not though. The only engines in that range (huge.) that I am aware of are the; Thunder Tiger
pro-70BX, Thunder Tiger Pro-50BK, MGT 8.0, Hot Bodies .46, and the 7.7 GST engine.

Thunder Tiger pro-70 BX will offer you massive amounts of torque, but I doubt it will give you a better rpm range. Probably worse.


To get better RPM's, hp and torque, you'll need to go to a lower displacement, such as the Picco .28, LRP .28, HPI 5.9 Nitro Star, RB TM 928, maybe even STS .28 or .30.

Just depends on your price range.