hey guys i recently redid my 4.8 turbo set up with some better valve springs and while i was at it upgraded the ls6 style lifters i had in it to the ls7 style. with the ls6 lifter i used a 7.375 push rod and got just at or under 1 3/4 turns till 22 ft ibs. with the new ls7 lifters im getting a tad over 1 3/4 turns and when i fired it up it clanked and rattled like all heck. it finally started to idle quietly as i left oil pressure flow threw the lifters but as soon as i would try and rev it it would get noisy again and clank around and stall. i think the push rods are to long , after reading around i think i want to order a push rod thats 30 thou shorter. the chart i saw said that 30 thou would equal about a 3/4 of a turn and im a tad over 1 3/4 now. does this all sound correct? so if i have a 7.375 now i want a 7.345 correct? also does any one think i hurt any thing running it? it does run quiet as long as i let it idle if i rev it thats only when it starts to clank around.

 

oh and after you take a look please feel free to reply lol 63 views and no replys isnt good.
also added a video 2012 08 26 13 07 51 872 - YouTube

 

not a good noise. shouldn't hurt it if you don't drive it too long like that. i'd just pick a pushrod lenth checker. they are cheap. mine checked out right at 7.4 w/ stock lifters and cam base diameter. the lifters aren't pumped up fully until you rev it up.

 

That turn method BS is probably the worst thing to come along in years...

Get a pushrod length checker for $10 and measure to see what you need.

 

What cam and thickness head gaskets are you using? FWIW I needed 7.350" rods with LS7 lifters, stock head gaskets, stock base circle cam.

 

This is the best advice.

Although measuring that way can give you a round about idea of what length might get you close, I will have to agree with you 100%!