Tri5Nerd

iTrader: (3)

I have all parts ready to do a H/C swap, the last thing I bought are the LS7 lifters.
Thanks to PREDATOR-Z I have the combination setup for a nice swap.
I have 7.40 pushrods which is the correct length for the stock LS1 lifters with my combo, reading a few threads I'm seeing that I might need to go with .50 shorter pushrods if using the LS7 lifters, is this confirmed?

I would need to use 7.350 pushrods instead of 7.4, or should I get a pushrod checker and measure while doing the H/C swap?

85ta383

iTrader: (18)

you answered your own question.. get a checker ad find out the correct length!

PREDATOR-Z

Well on 2 threads with poeple using LS7 lifters, I've noticed that after measuring, they end up using shorter push rods than if old LS1 lifters were used.

I haven't been able to confirm that indeed the LS7 lifter dimentions, from roller to cup is perhaps .050 taller VS OEM lifters.

BIG_MIKE2005

iTrader: (116)

Man I really need to know this also. I got a set of 7.4 pushrods for my combo thats supposed to work. But I'm also gonna be runnin 5.3 heads milled .030 with FelPro gaskets that are .041 compressed.

I got the 7.4's under the impression that they will work fine. It sucks for me cause I can't really have any down time except the 2 days we are gonna work on the car over a weekend. And I don't have the money to buy 3-4 sets of pushrods just in case the 7.4's aren't right. So I'm tryin to research everything & match the right parts together the first time so we can just install it & be done.

warp10

iTrader: (5)

I have LS7 lifters with my combo (FMS13, LS6 heads, .040 Gasket and 7.400 pushrods) and it has quite a bit of ticking noises when warm but quite while cold. I order a pushrod length checker but I believe that the pushrod are too long.

Tri5Nerd

iTrader: (3)

Can someone who has installed these LS7 lifters confirm that indeed they are longer than the stock LS1 lifters?

PREDATOR-Z

That is the same issue than some other thread recently. No noise cold and noise when warm.

BIG_MIKE2005

iTrader: (116)

Maybe some sponsors that sell these on here could grab some & find out for us?? Possibly also anwser some of these questions as they are startin to pop up now since people started using them more recently??

I for one am very interested since this could be the only part of my build to affect pushrod length.

texinteg

iTrader: (4)

well the LS7 Lifter is the replacement for the ls1, so they technically they should be the same length according to gm. That doesnt mean that they dont need a different length push rod. GM with their infinate wisdom has been known in the past to replace parts and forget to mention needing additional parts to make the replacement work.

5ltrBetr

iTrader: (3)

Installed LS7 lifters in my 408 with 7.40 pushrods and stock rockers. No problems, no noise, rockers are showing centered with good geometry. I would say no, the 7.40 pushrods will be fine.

ls1muscle

iTrader: (16)

> LS7 lifters
> 7.400 pushrods

Some ticking when warm, nothing that bothers me. Silent when cold.

5.3LJimmy

iTrader: (10)

I used the LS7 lifters w/ an MS4 cam and 7.4 PR's. Stock heads and gaskets. It did have a bit of a tick when warm, but it was quieter than the TR230/stock lifters it replaced.

davered00ss

iTrader: (4)

I shouldn't have read this thread. I just installed AFR 205's milled .030 with a TR224 cam, LS7 lifters & 7.4 pushrods.

TorchRedZ

iTrader: (10)

Im using the 7.4 pushrods with ls7 lifters.

Bandit LS1

iTrader: (2)

I am curious now too, I'm about to install the LS7 lifters in my LS1 with a F13 cam and unmilled Dart 205 heads. I have a set of 7.400" pushrods and want to do it right the first time.

Ryan02SS

iTrader: (3)

Do it right and buy a pushrod length checking tool. I can't believe some of you guys are not worried about your motors ticking at warm idle! Did your stock motor tick?
There's only one way to do it right.

Tri5Nerd

iTrader: (3)

I think you should be OK, it appears that the folks that milled thier heads might need the shorter pushrods. I'm going to get a checker for my install.

5.3LJimmy

iTrader: (10)

Yes my stock motor did tick. It was quieter w/ the LS7 lifters than it was before(stock/previous setup). But I do agree with the push length checker. I just brought the rockers to zero lash and verified that I had between 1 & 1 1/2 turns of preload. While this may not the best method or most the professional, at least I can say it was close.

BAD2000TA

iTrader: (6)

I totally agree. I had a problem with bad ticking when my motor warmed up. I have MTI's Stealth II cam (XE-R lobes) and .020 decked LS6 heads. The push-rods were Trick Flow 7.40 and I am using the GM MLS gasket. I ordered the push-rod checker and I verified the length on four different lobes. I came-up with 7.30 at zero lash. Adding .080 for preload, I need 7.38" push-rods. I ended-up shimming the rocker shaft .020 and the ticking was dramatically reduced.

brian

3fourty6

iTrader: (2)

I am running 7.4 pushrods with my LS7 lifters, MS4, and Stage 1 PRC heads. Sounds like a sewing machine. As far as ticks go I can't say it's any worse than stock. I've heard of other people using shorter pushrods so I ordered the length checker and it came out that 7.4's worked best for me even with the different base lobes between exhaust and intake.