2006 4.8 Silverado p0308 Misfire on Cyl #8

[STL_G8GT]

I didn't know the truck was working on its own custom grind cam

[imajeenyas]

^ This is your cam on drugs!

[EricL9]

No bueno. Time for a new cam and lifters. Fun times.

[STL_G8GT]

New cam is on the way.

I still have my non-dod lifters from when I did my G8 cam swap at 15k miles. All were in perfect condition upon removal.

Any reason not to use them in this repair?

RockAuto parts lists either the HL124 (GM PN 17122490 - individual "ls7" lifter) or the HL128 (GM PN 12576400).
GM Parts Direct shows 17122490 for both the 06 Silverado 4.8 AND 09 G8GT 6.0.

The GM spec'd pushrod is the same for both engines.

The lifter that came out of my G8 looks a bit different than the one found in the 06 4.8.




I found this chart that shows preload differences in the two part numbers.
LSx Lifter Preload Update.jpg

As best as I can tell, the HL128 is what came in the 06 Silverado, whereas the HL124 is what was in the G8.

Now, when I search for lifters for the 06 Silverado, the replacement part is listed as a HL124.

As I see it here are my options...

Replace the faulty lifters for cyl 8 with two from my G8 - or replace the whole passenger bank with the G8 lifters. I'm concerned with the dimensional (length and preload) differences between the two when installed on the same valvetrain.

Replace the faulty lifters from cyl 8 with two HL128 replacement (sealed power HT-2148).

Any opinions?

[STL_G8GT]

Cam is in, runs like a champ. Used the two ht-2148 because I just wasn't comfortable mixing and matching lifters.

The interesting thing is that the entry level morels are identical body wise to the first design is lifter (the hl128 or sealed power ht-2148).

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