novasteve

Alright guy's I have a friend that has a 70 c-10 with a really stout 355 I don't have all the specs on the engine but since he put it back in his truck a month ago after being built it has broken 2 rocker arm studs what could be going wrong here? could it have the wrong size push rods and not have the correct angle? or anything else?

kenSS

iTrader: (1)

could be any of those. most of the time when you brake a rocker stud its because the lift of the cam is to much for the rocker. if they are a stock style rocker. if it's a roller rocker than it sounds like valvetrain geometry problem to me.

ZONES89RS

iTrader: (25)

Well, when you say "stout" there is the possibility you are one of the many that are out there who are the reason they make 7/16 studs. I have them, unless you do too then you have issues.

novasteve

Yeah it's got 7/16 studs comp NSA rockers and guide plates.

meandmyls1

You have big problems.
No info at all about this engine. OK it's a 355 with 7/16" studs and non self aligning rocker arms.

What do you expect to hear if you have no question?

Look at:
coil bind
retainer to guide clearance
piston to valve clearance
retainer to rocker clearance
exessive spring pressure-make sure it's set up for the cam
pushrod to guide contact
pushrod to pushrod hole in head clearance
valvetrain geometry
rocker to valve stem tip pattern
rocker nut to rocker clearance at full lift
rocker stud to rocker at full lift
lash adjustment
worn cam lobes (can cause the pushrod to push the rocker base and increase lift)
make sure the valve to guide clearance isn't too tight
ALL THESE TESTS NEED TO BE CHECKED WITH A SOLID LIFTER IN PLACE IF THE CAM IS HYDRAULIC.