nitro the front isn't limited thats all it will go up before the tires start lifting. with a jack the car will only go up 2.5" from the front spindle to the ground before the tire comes off the ground. the rear is stock with caltrac the front has 350# springs. no slicks drag radials and the pressure is 15psi doesn't do any better lower. we got to 3800 on the launch and ran out of track time. the engine is a 555cid. the same combo goes 1.26 60ft in my car and runs 8.30s