I have a 74 pony 455 standard bore, pistons and non decked block. 46 6h heads, xe268 cam, edelbrock performer intake with edelbrock 750 carb,roller rockers and headman headers with th400 and 3.73 posi in a 77 T/A. It goes but i was really expecting more . No i have not dyno it nor been on the track. Any suggestions?