fixinitup

iTrader: (6)

So I have a set of Ls1 (853 casting) heads in the garage and my dad's work truck with 706 heads have cracked... BOTH sides, I guess this is a common enough problem with these heads. I searched already and found that milling .028-.035 with the right gasket will bring compression up to stock 4.8L specs, but nobody says anything about having to buy new pushrods. I think I read that if milling more than .02 new push rods need to be bought?

Does anyone have experience with this? What is the range of preload that needs to be on the lifter? And I'm pretty sure I know the answer but are the pushrods same length between LS1 and 4.8L?

Thanks,
Jake

Burken01

iTrader: (88)

A pushrod checker is $20 and removes all doubt..


You don't want pushrod length advice over the interwebz

big hammer

stock pushrods for an ls1 are actually around 7.380. lots of guys went to hardened 7.4's with no problems, but this will but the pre load on the tight side.

ideal preload is between 1\2 to a full turn on the rocker bolt after pushrod to rocker contact. outer limits is 1\4 to 1.25 turns.

with milled heads you quite likely wouldn't get away with 7.4 pushrods. stock ones might work, you'll just have to check your pre load.