valve train issues

[mopar540]

hy my friend ask me for an issue in his engine a 520ci mopar engine with indy 440-1 head fulluy ported with larger valves he puts .125 larger valve than the stock ones and he start to brake the pusrods and the rocker shafts , i was thinking on mill the shaft blocks on the heads?
maybe that would resolve the problem appreciatte your time and answers

thanks

[John_Heard]

Almost impossible to answer a question like that Alberto, there are a ton of things that can cause valve train problems. The entire combination - rockers, valve length, pushrod length, spring height/installed height all that stuff comes into play.

[Yellowchevelle]

Almost impossible to answer a question like that Alberto, there are a ton of things that can cause valve train problems. The entire combination - rockers, valve length, pushrod length, spring height/installed height all that stuff comes into play.

X2 also check valve to piston clearance