Pushrod Problem

I have a chevy 305 and i installed 350 vortec heads, roades lifters and i have a mild flat tappet cam and edelbrock springs. everyone i know says that the stock pushrod should work. but when i started the engine all the pushrods bent and 3 broke. i thought that i adjusted the valves wrong so i bought more pushrods carefully adjusted them and when i started the engine the same thing happend. all the pushrods were bent and the same 3 broke. the engine runs fine for about 10 seconds before the pushrods bend.

my question is do i have the right size pushrods or is there something else thats wrong  

did u have none vortec heads before?  

"did u have none vortec heads before?"

Yes Yoda.... had before none vortec heads...

And if that doesn't clear it up for you read below.


You obviously have a serious problem, you should get an adjustable pushrod to measure and then order the correct size.  

How did you adjust the rockers.  
Horsepower sells Engines and torque wins races.

did you check valve spring clearance?  

ya i have clearance with the valve springs. i adjusted the valves by making sure there was no lash then 3/4 turn after that. i ordered a adjustible push rod form summit racing so i can find out what size pushrod i really need. whats weird though is that when i have everything adjusted i can put a 1/2inch ratchet on the crank pully and turn the engine over just fine. so if something was bottoming out or getting jammed up you would think i couldent turn the engine over with a ratchet.  

in what order did you adjust your valves?  What method did you use?  You can't just adjust them all at once.  

Pushrods for Vortec heads are shorter, if you set the two heads together you will see an obvious difference. I just noticed this the other day, if you put roller rockers on a Gen 1 head you need tall covers for clearance, if you put the SAME roller rockers on a vortec head you can use the stock cover  

3/4 of a turn pre load is too much you only need a 1/4 turn of pre load.  
Horsepower sells Engines and torque wins races.

Factory shop manual says 1 full turn for a SBC. Look it up  

Ya! ok setting the preload 1 full turn down from zero is a great way to wear performance parts out before there time it can also cause the valve to be lifted off the seat when the lifters pump up before the valve is to be open.
OH and the manual I have says 3/4 turn from zero.  
Horsepower sells Engines and torque wins races.

Ya also what method did you use when adjusting your valves, how did you know if the lifter was on the heal?  If you have ever read anything from the cam manufacturers you would see most recommend 1/2 turn.  

I looked up the instalation instructions that came with my Edelbrock Cam and Lifter kit, they recommend 3/4-1 turn with their roller lifters.  

ok and how did you go about deciding which ones to tighten when?  

this ole dog learned a new trick from smoke and pontiac....

my dad always told me God gave us two ears and one mouth for a reason...listen up!!!