Putting some new heads on . new merlin heads cast 1-043 i have a hp 465 with a 731 cam and dart intake . Taking off stock mer heads . what power increase will i see ,if any
thanks

Better have them checked. I bought a set and they didn't machine the valve guides down. Of course that fragged my timing chain among other things. Guess what, they didn't pay for it.

That's okay though because I figure I've cost them over $15K in new customers!

You will need some different head bolts on the exhaust side. I have 2 sets of those heads which just got ruined
Too much milling...