I put a 1991 H.O 5.0L in the II (With Edelbrock Performer Heads). It has taken me almost all summer to get it working good. I have been messin' with 302 Fords half my life, but the H.O had me stumped! I finnaly was at wits end, I bought a wide band 02 kit from AEM. The carb was set-up for the old 302 with thte Edelbrock Perfomer cam in it. It turns out that the carb was running really rich. (off the gauge at idle, at cruise and at W.O.T Which I found really odd because the plugs looked perfect dusty brown. The H.O likes at least 10 degrees of base timing and only 30 degrees of total. My old sweet spot was 6 and 34! The carb is now set 1 stage leaner then the base set-up for the Edelbrock carb. I may go one step leaner yet because the air fuel still dips into the very rich 11:1 territory when you floor it. It was getting really lean when you rolled into the throttle with the secondarys closed, so I put the pink step-up springs in which fixed it. This summer's lesson was a H.O is not a 302 when it comes to tunning!