Thread: cylinder heads

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Push rods are NOT the same length. Roller lifters have a 7.122 inch long pushrod while the older flat faced lifters use a 7.724 inch long pushrod. For the rocker arms, you either
need guided rockers or non-guided rockers......how to tell?

Earlier heads used the head casting to guide the pushrods OR they used
stamped metal guide plates that bolted under the rocker studs. They can be identified by the rather narrow pushrod slots.

Later model heads (including the Vortec heads that you dont have but everyone wants you to) have larger holes thru the heads.....this was done at the same time that roller lifters came into being. Instead of guiding on the head, the pushrod is guided (side to side) by a slot on the valve end of the rocker.....since the pushrod fits into a pocket on all chevy rockers, they guide the rocker side to side play on the valve side.....

So, if you look at the underside of the rockers, you will either see a flat surface for the valve tip contact OR you will see a depression (slot). If your heads came with rockers, use the same style that was on them and you will probably be OK.

DO NOT put guided rockers on a guided head....you will discover push rod bind, a term that promotes bad words and thrown tools.

guided on left, old style on right