I am in the middle of a cylinder head repair on a 2008 Z06 - heads are currently off and having the valve guides repaired.
I would like to replace the lifters with a set of stock lifters, just for peace of mind - anything I can do to minimize the chance of having to pull the heads again would be great.

Unfortunately it seems that part # 12499225 (which is for a set of 16 lifters) is on indefinite back-order nationally - possibly due to COVID19 situation?

I did some calling around to various dealerships and performance shops (local (Buffalo NY) and out of state) and it seems there are multiple part numbers that come up for these lifters.
For instance, 12499225 seems to correspond to 16 individual 17122490 lifters (AC Delco HL124?) - listed on various GM parts websites as stock replacements - not correct accordingly to the dealers however.

The local dealerships list 12648846 as the current part number for C6 Z06s individual lifters (12648846 seems to be a succession of part # 12576400) - both the 12648846 and 12576400 numbers seem to correspond with AC Delco HL128 - and on various GM parts websites they come up as replacement lifters for the 2014-2015 Z28 Camaros (same LS7 motor, same heads, same pushrods, rocker arms etc. as per parts websites) - but NOT for the C6 Z06?
Does anyone have any input on this? Are these interchangable? Are some 'good' lifters and others 'bad'? I would prefer not to use a 'performance' lifter (such as the Cadillac racing lifters) due to wanting to avoid additional engine noise, and I'm currently keeping the stock cam. Obviously I could wait until kit # 12499225 is available again - but I would prefer not to end up waiting for weeks until I can reassemble the car.

Thanks in advance - any input is massively appreciated!

 

Got a used set of Comp Cams 850-16 lifters maybe 3000 miles on them $125 shipped, went solid

 

Use the good GM Performance lifters that you called (cadillac lifters) p/n 88958689.They are the best lifter that GM has.They are not any noisier than any GM lifter.Mine are quieter than a church mouse.They are available from Juicedmotorsports a vendor here on the forum for about $279. for the set.They will never get noisy unless you put a stupid amount of pre-load on them

 

I'm not necessarily opposed to the 'Cadillac' lifters - but it seems there are a ton of horror stories associated with them. Do they work with stock pushrods?
They'd be going into a stock motor, with stock cam - Katech head repair however, so bronze valve guides, Katech TiMo intake valves, OEM exhaust valves, etc. I don't think they change the valve springs.
At some point down the line a mild cam might go in it - would be nice to install without having to pull heads again... not sure how tolerant Caddy lifters are of a mild cam compared to stock LS7 lifters.
Thanks again!

 

I'm running the Caddy lifters on a fairly mild cam. 226/234 115+4 lsa with .620 lift on both valves. My experience is that they're a little sensitive to too much preload. I didn't measure for lifter preload (just shoot me). I checked enough valves to see that, with stock length pushrods, it took 1 and 2/3's turns past 0 lash to get to 22ft/lbs on the rocker bolts. Figured this was OK with everything I've read regarding lifter preload. Wrong. It laid over and died at about 6250rpm. My LS3 had ported heads, ported and rod modded intake manifold, and all the other bolt ons. No way it should have quit pulling at that low of an rpm.

Fast forward a few weeks after lots of head scratching. Installed 7.35" pushrods and all is good with the world. It took a little more than 2/3's of a turn past 0 lash to get to 22ft/lbs. She pulls clean through 6800 rpm now. No excessive valve train noise either.

 

They work perfectly with stock length 7.40 push rods unless you go full retard on pre-load which will kill rpm of the engine same as any other lifter with too much pre-load.Valve train will be whisper quiet

 

Op what did you end up finding/ordering? I’m in the process of replacing the heads on my 09 with some ported heads, pac dual springs, yellow terra rockers, ported tb and intake and mild turbo cam. My 09 has 90k miles on it and I wanted to replace the lifters with fresh new ones but no one has them. Even the aftermarket is depleted. I called Juiced and same thing. Guess I’ll have to reuse the old lifters.

Question: is there a difference between the factory ls3 lifters and those out of an 08 z06 ls7? I have a few ls7 lifters here.

thanks

 

I don't think there is a difference between LS3 and LS7 lifters - I ultimately got part # 12499225 from GMPerformanceMotor - Gandrud Chevrolet's performance parts online store. I spoke with Jason he wasn't able to 'reserve' a set for me, but he did alert me when they got in some stock that wasn't already bookmarked by speed shops and various authorized distributors.
Everyone seems to be saying between GM strikes and COVID19 situation that they are backordered - but various places DO get a few lifters here and there and are able to sell them; my advice would be just to call around and keep at it - if you're persistent I think you'll manage to get some, but it may be a week or two - but shouldn't be weeks on end.

 

Just an FYI...lsxceleration had 10 sets (9 now). Everyone else said back order no date provided. These are the Delphi’s so hopefully they are as good as factory. From what I understand Delphi makes them for gm. Thanks