FRH GM 243/799/317 6L LS1
Seriously fresh, seriously powerful! For those looking for aftermarket performance, these reworked factory castings offer a much more economical solution while still offering similar power potential. Leaving the already large stock combustion chamber as‐is, the intake and exhaust ports are designed to utilize larger valves than originally equipped and CNC machined to provide superior surface finish and the ultimate in repeatability. The new valve job is precisely matched to the new port design further increasing the efficiency of these heads. All of the mating surfaces have been CNC milled using PCD to not only provide a flat, clean mating surface but also to correct for any angular discrepancies in the stock casting.
Click for larger view:
Intake Volume 225-240cc
Exhaust Volume 88cc
Chamber Volume 59-70cc
Intake Flow (2.040" Valve)
262cfm @ .400”
320cfm @ .600”
Exhaust Flow (1.575" Valve)
200cfm @ .400”
240cfm @ .600”
Spring kit w/ Titanium retainers included good to .660” lift
Intake Valve Diameter 2.000” - 2.040"
Intake Seat Material Ductile Iron
Exhaust Valve Diameter 1.550" - 1.575"
Exhaust Seat Material Ductile Iron
Valve Angle 15⁰
Valve Guide Material Bronze Alloy
Minimum Bore Size 3.900”