[ron mattson]

1 those heads are all good and very similar
In both flow and hp.
2 the 487x is allowed but there is more of
A difference between good castings and
Bad castings than there is from one casting
Number to another.
3 horsepower can vary greatly from one
To another but 410- 430 depending on the
Dyno will get you down the track very well.
I have heard of some making more but the
Best dyno is 1320 ft long and it does not matter
What the dyno sheet said it made its the
Et ticket that does! Hope that answered your
Questions.