I am using Fel-Pro 9333 PT1's on my Lightning with aluminum heads. These head gaskets are originally for 1985 5.0 HO Mustang. My friend Speedy told me about these head gaskets and I have not used anything else since. They have been tested on 800 hp engines by Ken Dutweiler. I have used them on my 351 N20 set up with my N20 system set at the 200 hp level and I am currently using them on my 410 n/a combo. No cooling or sealing problems at all. I have a friend who used them on his Vortec powered 351 in his Lightning with about 12 lbs of boost with no problems either. He had a misfortunate rod bolt/rod failure resulting in a damaged engine but his mighty Fel-Pro 9333 PT1's never failed!! These head gaskets are awesome and are only about $18 a piece. I like them very much and will never O-ring my heads or block because of my confidence in these headgaskets. The best feature of all I like about them is a feature by buddy Hotrod told me. "Standard headgaskets act as your fuse should things go crazy" No forged piston, forged rod, or O-ringed set up is going to withstand detonation for long. Its all in the "tune". And thats where its at.
Thank you,Edward Huerta/Struckby