I have a 1993 502 BBC motor, what kind of gains should i exspect with these engine mods? the stock 502 is 415 to 420 H.p I dont have spicific part numbers for the up grades just wondering if I did these changes what should I gain from It.
1) Lighting stainless steel exhaust headers
2) edlerbrock intake
3) stock 850 cfm holly 4 barrel carb
4) com cam
5) roller rocker ( valve job also)
6) HVH 2" carb spacer
7) stock ignition (spitfire omc)

With out knowing what the cam grind is a horsepower guess is impossible. The Headers are most likely good for 20 hp on a stock engine, intake 5- 10 hp, carb spacer could do anyting from +15 to -15 but on a mostly stock engine I doubt it will do much.

With these mods i dont feel like there will be much and probly wont run any faster. Maybe one mile per hour faster. just from my experience and my 2 cents.