I just got through dynoing my .040 over 454 with edelbrock performer rpm heads and intake. I ran a howards hyd roller (108 lsa installed on a 104 icl). I was pleased with the torque output (500+ ftlbs up to 5000 rpm), but the rpm band didn't really match the claimed 2500-5800 spec. The engine peaked at 5200 (490 hp), and started falling hard at 5400. I know a tight lsa will fall hard , but I had hoped for at least a 5500 peak.