so i built my motor for my iroc last summer couldnt get it running due to the timing chain/gears being installed wrong i took it apart re did it yesterday and got the chain in right at least what i thought was right the car fired right up ran good i mean it was off a little due to the timing not being set but it was running no stalling or sputtering i let it run for a good 10 15 minutes everything looked and sounded good so i buttoned it up put the valve covers on and started the car and started to set the timing as soon as i put the timing gun on it i started getting a loud tick and a few backfires so i shut it down pulled the valve covers off and i had 2 snapped pushrods and 6 more were bent all on the exhaust side intake side was good. now i have new pushrods in the motor but i need ideas or suggestions to remedy this problem before i start it back up cause i dont wanna break anymore pushrods or break anythin else... please go into detail this is my first motor ive built so im kinda new to this

 

if you mis-aligned the timing chain... did you do valve and piston damage... or did you over tighten the push rod adjustment nut????

 

the problem is i dont know where i messed up at but with it being all the exhaust side rods were bent/broke i highly doubt they were over tightened cause i did them one by one to spec while turning the motor by hand. the timing set im using has three different slots where it can be installed on the lower gear so im guessing its on the wrong slot so im gonna go get a new timing set that can only be installed one way and try that

 

if this cam was close to stock... and stock heads
I experimented with 0, advanced & retarded keys with a 327/350HP cam
never any bent push rods... I used to run that combo 7,000 rpm's all the time