lt1rx798

i have a solid roller set-up in an lt1. recently i had a set of valves put in a set of lt4 heads. i think the new valves were .01th longer than the stock lt4 valves. now my comp 7.800/.080 pushrods are too short. do any of you know what length rods i need? btw...i also have jesel shaft mount 1.6 rockers.

i haven't measured them yet, but they appear to be 3/4 to 1in too short.


the lt4 vales are for sale btw....

seawolf06

I would say get an adjustable PR length checker. Should get pretty close b/c you have solid lifters.

shoebox

You can't guess. Measuring is the only way to know.

lt1rx798

i know....i was hopeing someone had swapped from lt1 to lt4 heads and happened to know the difference in length, or maybe a part number of the new rods....i could get the measurement and subtract .010 because the only thing that have changed was the valves and heads.....i take that back, the springs are also new, but the valves can only close one way, so that dosent matter.

anyone with have a clue? if not, what is the best way to measure them w/o the adjustable rod?

lt1rx798

sorry..2x post!

lt1rx798

anyone in baton rouge w/ adjustable p/r i can use for a few minutes?

Projectz28

just changing from an LT1 to and LT4 head will not... or should not make a change in PR length. The difference between the 2 heads is in the runners. The valves are the same length on LT1/4 unless someone changed valves.

There is no way to know... you must measure with an adjustable PR. They are cheap. You can pick up a checker at Summit or Jegs for $10.

BTW, if the new valves you are using are longer they are probably .100" longer and not .010"

There are just way too many variables to calculate PR length. Just because the new valves are .100 longer does not mean you need a .100 longer PR.

BTW, I am running TFS LT4 heads, Ferra +.100" valves, .039 gasket and Jesel SS rockers and ended up with a 7.850 PR on my SR.

lt1rx798

thanks for the reply.... you are right about the additional length, but my lt4 heads are about 1/4 of an inch taller, which im sure dosen't affect the push rods, but there were after-market valves in the lt1 heads, so i will do it right and get the adj. p/r. ....thanks again!

seawolf06

Just run to Thunder Racing and get one. They're cheap. BTW, those are the longest PR I've seen in a LTx motor.

lt1rx798

i ordered on from summit.

i have been known to get my numbers mixed up, but those numbers came off the side of the rods........

thanks for the help guys!