CasperCasper

I am currently trying to figure out the pushrods on my LQ4/L92 build. Heads will be milled .020 with stock GM head gaskets. I was sent 7.4 pushrods from Texas speed. After measuring the pushrod length with zero lash, I then subtract my preload from pushrod length. My question is how close does this measured length need to be to the pushrod length. For example, if I measure an ideal length at 7.350, so .050 difference, do I need different pushrods ? What is the threshold here ?

thanks

Josh

kinglt-1

iTrader: (26)

You do not subtract from the length, you add it to your zero lash measurement.

For example, If you are using LS7 lifters, most run a preload of .080-.100, so that would be a total length of 7.43-7.45 if your zero lash measurement was 7.35.

Tolerance is based on the lifter travel. Lifters like LS7's have quite a bit of plunger travel, so they can be more forgiving if the push rod is slightly longer/shorter then what was measured. However many aftermarket lifters with reduced travel would require more precise measuring and potentially custom push rods to hit the target measurement.

CasperCasper

The lifters are a GM replacement. They are melling part number J2079. I am assuming I go with factory preload setting here ?

kinglt-1

iTrader: (26)

yes...