justout4u

iTrader: (3)

did you measure pushrod length or did Pat G suggest 7.350. I have ls7 lifters and 243 heads milled to 62cc and Pat said I use the 7.4 pushrods, not sure about 317 though. Keep us posted

1nasty86

iTrader: (63)

The 317's are milled to a 64cc chamber so I have no idea what pushrod I need honestly. And I have stock .051 head gaskets

01ssreda4

iTrader: (96)

Nobody is talking about stock cams. He has an aftermarket cam. So allow me to answer his question....Yes aftermarket cams run smaller base circles then stock cams.

1nasty86

iTrader: (63)

After reading about pushrod length I remembered while tightening down my rockers I go about 1 full turn past zero lash before it hits the 22lb mark. I read its suppost to be 1.25-1.75 turns past for proper preload on ls7 lifters... Could too short a pushrod cause this noise im hearing?

01ssreda4

iTrader: (96)

I would say yes it can.

TJ

iTrader: (10)

this may not pertain to anything, but my work truck starting tapping. 150K on the clock, it was making a HELL of a noise. for sure on driver side. pulled head, replaced lifters..... noise went away. noise comes and goes, so i pull pass side head and replace lifters. noise still comes and goes. rattles for about 5 minutes once a day. ususally starts when under a load, then dissapears. im starting to think ive got a rocker going south, even though i inspected them when i had the heads off and they appeared fine.
OR ive got a cracked flexplate.

something to think about with your random noise.

1nasty86

iTrader: (63)

needle bearings in your case maybe? unsure. but i checked again today, its exactly 1 full turn past zero lash where it hits 22ft lbs. should i buy 7.375 or 7.400 pushrods?? and again could this be my noise

1nasty86

iTrader: (63)

using the pushrod length checker i put it at what roughly 7.375 and torqued it down... took 1.25 turns put it at 7.400 and took 1.75 turns. so what pushrod should i get?

joecar

Can't you use the PR length checker to measure the zero lash PR length and then just add the lifter preload...?

1nasty86

iTrader: (63)

Fingers are too fat lol. From what ive read/seen/figured im going to need the 7.375 pushroda to get me in the right area. But I wouldnt think the .025 difference would cause my noise. Only time will tell.

TJ

iTrader: (10)

more preload is better than less preload, IMO. i dont recall the actual spec, but the ls7 lifters have some forgiveness. there is a pretty good range they will operate.

1nasty86

iTrader: (63)

Also used the pushrod length checker and came up with 10 turns. So add .080 for preload and I come up with 7.380 so I do need the 7.375 pushrods. But still could this have been my noise?

TJ

iTrader: (10)

i am almost positive mine are at .074 and mine is fairly quiet for the cam specs.
a few guys will tell you that you can squeeze .100 on them.

1nasty86

iTrader: (63)

I should be at .75 with my new pushrods. Most likely was at .50 before. Maybe my noise was comming from this.... But who knows. I remembered this morning that I also changed the converter close to the rocker upgrade... Ill be looking for backed out bolts also. But if I recall lock tite was applied to all 3 bolts.