LS7 lifters
#12
PT's Slowest Truck
iTrader: (19)
Originally Posted by Ferocity02
Right, but checking the pushrod length and then ordering the right ones adds days/weeks onto the build, which isn't really an option when it's your only vehicle. I was hoping someone could throw in their two cents.
I understand that you need the right pushrod the first time around, but your truck will be down longer if you take out a new set of lifters. The stock pushrods are 7.38, most guys with stock heads run 7.4 when swapping in an aftermarket cam on a pre-DOD GENIII, with no problems. There are pics floating around here that show the LS7 lifter cups to be taller than the original GENIII factory lifters, which has to be factored in. Cam base circle also has to be factored in. If the heads are milled, that needs to be factored in. If it were me, I'd buy the pushrod length checker, and a few sets of pushrods that are in the spectrum of possible correct lengths, then use the ones that fit and send the others back...or you can play roulette with what has worked for someone else, or someone else's buddy on the net...
#16
PT's Slowest Truck
iTrader: (19)
Here ya go, 12499225, $121.95 for a set of 16 from SDPC (sponsor)
http://www.sdpc2000.com/details/gm-p...parts/12499225
http://www.sdpc2000.com/details/gm-p...parts/12499225
#17
So for example, start with 7.4 on the checker, install the rocker arm, tighten the bolt to zero lash then set the dial indicator and zero it. Torque down the rocker bolt, wait a moment or two for the oil to leave the lifter and measure what the preload is. If it's too high, then start over with the checker at 7.35.
#18
PT's Slowest Truck
iTrader: (19)
This is my favorite sticky :
https://www.performancetrucks.net/fo...d.php?t=440262
Richard at WCCH recommends .040 to .080, .060 being ideal
https://www.performancetrucks.net/fo...d.php?t=440262
Richard at WCCH recommends .040 to .080, .060 being ideal
#19
This is my favorite sticky :
https://www.performancetrucks.net/fo...d.php?t=440262
Richard at WCCH recommends .040 to .080, .060 being ideal
https://www.performancetrucks.net/fo...d.php?t=440262
Richard at WCCH recommends .040 to .080, .060 being ideal
#20
TECH Senior Member
iTrader: (59)
Fortunately these LS lifters are pretty lenient with preload. I've seen people running .030 to .120, although I wouldn't recommend either of these. I'm going to shoot for 0.080. I went ahead and ordered a Comp pushrod length checker for my rebuild. For $16 is cheap insurance. I also ordered a set of 7.350" pushrods. If I don't need them, I will sell them.