rocker question

[4onFloor]

will 1.6 rockers work on a mid 70's 350 block(stock pistons) with 89 305 heads? the guy that owns this engine says they'll work, but i have my doubts. i think the pushrod slots would probly have to be enlarged but i dont know. any thoughts?

[68chevelle]

i think they will work. look at the pushrod slot. if its actualy a slot then it should work. if it is ALOT more like a circle then it will need to be enlarged. i dont know how the heads were in 89, it might it might not. if your still unsure, then just buy the pushrod slotting tool and make them bigger. they dont cost that mich i dont think and its not that complicated.

[Deadcarny]

they will work, the only thing to think about is Coil bind on the springs and Piston to valve clearance.

[68chevelle]

yeah you will probably need new springs for sure. as far as hitting the pistons, if the piston has valve reliefes then your cool, if not i dont know if i would even concider it. but it also depends the total amout of valve lift that it will have.

[GTStang]

Bottom line is anytime you do something like this unless someone has done the exact same set-up with everything the same. You need to assembly it and spec it out especially the piston to valve clearance. You can make educated guesses and math it out a bit but it ends up you have to take the time and tolerance everything to know you were right.

[1992RS]

If you have a mild cam then you won't have any problem at all with springs or valve to piston clearance, if you have a hotter cam then you need to make sure that your springs are rated as such. When you buy springs they'll give you the gross valve lift specs. Then take the lobe lift on your cam and multiply by 1.6. If you have a built engine then I'm sure you have valve reliefs and that won't be a problem. If not then I would invest in some new pistons. But that's just me.

[Deadcarny]

Stock cams with 1.6 Rockers are usually VERY close to coil bind, and in some cars are beyond coil bind. Most stock Performance GM springs coil bind near 0.500".