As most already know port matching the FAST intake manifold to your head's intake runner yeilds some power gains but a word of caution; you absolutely must have a specific port match done to your heads.

For those of you considering this manifold but use stock 243 casting heads very little (if any) by way of manifold material removal will be needed.

I disassembled my FAST and placed it onto my slightly ported heads with the intention of performing a port match only to find that the only places that there was any material to be removed for a port match was actually on the bottom of the head's intake runner. The size of the stock intake ports is closely duplicated in the FAST's runners. There appears to be a smoothing of the FAST's runner and the removal of a ridge that is done by FAST porters but not much will work by way of enlarging the FAST's runner itself. If you do enlarge the runner then the head's intake port opening will be smaller and that would yeild a flow disruption.

Hope this helps anyone thinking about getting and porting this manifold with stock heads. Also, any one contemplating the disassembly of the FAST should have some RTV silicone handy to assure the proper seal of the manifold after you break the seal. I'm sure I over did this step but it was worth it since the car's idle was much better upon completion suggesting that I had some air leaks in the prior configuration. It was raining so a test drive will have to wait for sunny skies.

 

Thanks Spin...
Jeremy