tfs1 with the cheap spring kit off summit ( 110$ ) zero float and pulls all the way till 5700.

 

if this is going into your truck DO NOT put an X cam in it. X cams with stock type heads are useless in a mustang let alone a heavy truck. just use the stock explorer cam which is designed for torque in a heavy vehicle or maybe a stock HO cam. any performance cam will kill driveability and need a loose converter and gears to make work. good luck.

 

 

I put in a Comp Cams XE264HR with 1.94I/1.54E and .550 lift springs on GT-40Ps, with a cobra intake and it runs out pretty damn good and with a good idle. I need to get it to the dyno and see what is putting out. Specs are valve lift is .512 w/264I/270E duration.