The dyno that it was used was a mustang dyno and my horsepower does not drastically fall its more gradual. As for the heads they have been modified by scoggin-dickey for the LT4 springs, which are rated for lift up to .525. I know this is pushing since the cam has that exact lift but I would think that if valve float was my problem horsepower would have fallen dramatecilay and it didnt. From my peak horespower at 5000 rpm (258 hp) it only fell to 246 at 5500 rpm. I wouold think that if it was valvefloat it would have fallen more steeply.

I am thinking I might try a mechanical fuel pump since my car was origional a TBI and I am still useing the stock one. Also I dont know how I could be reading my a/f ratio wrong because I have a sheet which lists it at 40 rpm increments from 3000 grand to 5500 and it never got above 12.9