906 or 452 which is best overall

Alright then, back to the thread..........
There are so many ways you can set up these 452 or 906 heads one could get dizzy trying to keep track. Different porting methods and valve sizes cause the flow levels to overlap. One time the 452 will surpass the 906 and other times the 906 is the better. Here are a few examples of the flow differences between the heads and between different treatments in the same heads. These are from our records on our flowbench. We haven't done an all-out 452 or 906 in many years. Sometimes it will take weeks of work to do a set of iron heads. It's just best to get a set of new aluminum heads unless iron is required by the rules.

Oh yeah.......no epoxy or welding was done.

452........
Lift........stock IN/EX....2.14/1.81...bigger/1.81
.100.........61/55..........68/60..........85/59
.200.......130/108......142/130......164/124
.300.......188/152......205/187......220/109
.400.......213/172......248/218......257/224
.500.......222/178......286/234......294/245
.600.......230/181......292/245......309/261
.700.........NA/NA........295/253......318/274

906.........
Lift.....Stock IN/EX
.100.......65/57.......89/60.......80/61.......71/.......91/.......89/60
.200.....137/103...168/124...161/126...150/.....165/.....161/129
.300.....187/145...218/170...219/175...209/.....219/.....212/185
.400.....216/168...249/200...262/201...257/.....272/.....257/216
.500.....224/176...260/217...280/215...292/.....299/.....297/234
.600.....232/183...258/228...297/221...313/.....325/.....331/253
.700.......NA/NA.....258/236...297/224...321/.....335/.....347/264