Its also my understanding that you can run the 289 heads, and a .040 head gasket,however the bigger valves require the pistons to be pocketed for the intake valve,hopefully this is correct info
I’ve decided to run the stock heads and use a comp cams kit cam lifters springs etc from them.
you should replace the rocker studs with the screw in type aparently this is a failing around 6k
however with the stock heads a 1/4" needs to be taken off the stud boss to keep the correct ratio
I talked to comp cams about a cam recommendation they gave me a spec has more lift than a 289 spec ,you need to clay a piston and run it thru to get the total clearance piston to valve this will tell you how much total lift you can run,also we are using an F4B and a 600cfm carb and a petronix dizzy
comp cams liked that idea, also I talked to JE Pistons about pistons pricey at $1100 with pins & rings, Id like to run alloy heads also, however there may be an issue with the valve to piston.
get that book I mentioned probably help a bit some one sent me one got a lot of info from days gone by.