Trick Flow® Twisted Wedge® Track Heat® series cylinder heads are capable of producing 600+ hp on naturally aspirated engines--they're the winningest heads in NMRA racing. Twisted Wedge® Track Heat® heads so dominated that the NMRA saddled them with a weight penalty! Twisted Wedge® Track Heat® heads include all of the features of the famous Twisted Wedge® series heads, plus higher-rated valve springs (125 lbs. of seat pressure at 1.780 in. installed height), 10 degree machined steel super locks, and manganese bronze guides to support camshafts with up to 0.600 in. of lift when used with the proper pistons. Track Heat® 170 heads with Fast As Cast runners are perfect for dual-purpose street/strip cars and for racers looking for the best combination of performance and value. These heads feature cast intake and exhaust runners with Twisted Wedge® CNC-ported profiles. You get near-CNC-ported power and performance for the price of ordinary cast heads.