Does anybody know if one is really longer then the other? Alot of people say the LS7 is longer but dont know how much. Also what is the pre load for the LS7 lifter.

 

Good info in this thread. https://ls1tech.com/forums/generatio...-question.html

Difference in length and preload are discussed.

 

.050 longer

 

Just to verify something. The LS7 lifter is not longer, just the cup sits .06 higher than the stock LS1. This means when installing LS7 lifters, you will need a shorter length pushrod to stay within a resonable preload. Most likely a 7.35 or even a 7.325 pushrod will suffice depending on how much preload and valvetrain noise you want. As for optimum preload, the LS7 lifters is spec'd to be run between .06-.100 amount of preload or within that ballpark. Aftermarket lifters recommend different preloads, but this does not necessarily apply to the LS7's.

 

So I have 7.4's with the stock cam/lifters but want to do LS7's. I have adjustable roller rockers... am I good?

 

i got ls7 lifters and 7.4 pushrods, i compared them side to side and could see no size diffirent

 

It is not the length it is the cup sitting higher see pics
LS7 on left

 

It's very small as I read. So for guys using non-adjustables and issue but how about me with adjustables? Just loosen the lash a bit right?

 

I'm still interested in if all this is out the window if you have adjustables.

 

I run ls7 lifters, stock lenght chromoly rods, stock rockers and patriot dual springs with a tv2 cam, ls6 heads. over 5,000 miles so far everything is good and it makes great power.

 

Why is the LS7 marketed as an LS1 replacement when it apparently raises preload to unacceptable levels when using pushrods fit to stock LS1 lifters. I did everything right when ordering my custom length rods, excpet I used a solid LS1 lifter under the impression the LS7 was identical. This blows...

 

Don't forget most base circles on aftermarket cams are smaller, mine measured .050 smaller, so the higher ls7 lifter preload was allright with my stock lenght pushrods, plus the ls7 lifters have about .100 travel for automatic adjustment anyway.

 

Why do so many ask for pushrod length when the only way to know is to measure the pushrod length on the engine in question? Working on the internals of an engine and thinking that their are "stock" answers to these questions" shows an incredible ignorance.
Try that "one size fits all" at the pharmacy.

 

Changed to 7.35 for me, measure though to be safe

 

The LS7 marketed as an LS1 replacement was an ingenious marketing ploy done by GM, as per the owner of where I get my parts at. The true LS7 have a raised cup by .06 and it is not a stock replacement. The "LS7" LS1 direct replacement is an overflow of LS6 lifters that GM wanted to get rid of and make some money. There is no stock replacement LS1 parts in the LS7 engine not one part. Now if you want to make a difference the buy the CTSV lifters you can rev those to 8K rpm no issues, but they go for 500+ dollars. For the monye I was going to spend on the "LS7" stock replacements i spend a little more and got the Comp type "R" Pro Magnum and I have piece of mind.

 

I believe you have been a little misinformed. There is no marketing ploy, and you seem to a a little confused as to how it all works. The LS7 lifters are THE LS1 replacement, period. It is not an overflow of LS6 lifters that are used in a money making marketing ploy as you said, they are not any different that whatever you are calling "true LS7 lifters" because it is the exact same lifter. Please don't make public claims of such things as it is a rather slanderous accusation towards those of us who market the parts, and it is outright incorrect information. Both the LS7 and LS1 replacement lifters are the same part, and there are actually several shared replacement parts between the two, quite contrary from the "not one part" claim you make. Bearings, lifters, head bolts, freeze plugs, gaskets, sensors, etc are all the exact same parts.

The Caddy race lifters actually sell for just under $250, not over $500.

If you have any questions please feel free to hit us up in a pm or even call, we'll be glad to help you out with any answers you are looking for. We'll be glad to verify anything you hear from your parts guys if you think you might want a 2nd opinion

 

Owned.

 

x2 ouch lol

 

Owned indeed. I got my LS7 lifters yesterday thanks SDPC! I see the plunger difference and will measure regardless since I am going thinner gaskets. Maybe it will all work out in the numbers. If not I will have some low mileage 7.4 hardened pushrods for sale!

 

Ok, if they are identical what is your response to Predator-Z's post above?