GT40 heads can cost some money too, I have $850-900 us in my reg. iron gt40 heads, with purchase price, new comp springs, 5angle valve job,35 shave,tank, flux, new seals and plugs. I am about to drop $300-400 to have them ported (heavy on the exh., good all around clean up on the intake along with polished c.c.). with a new total of $1,150- 1,300 in a set of friggin iron gt40 heads. Sure I could have bought a set of TFS,AFR, EDL. heads but this is what I want to do.