Help identifying which GM lifter to purchase - Cylinder 5 misfire. 2017 5.3L Tahoe

[keithsmith022]

I'm going to be buying OEM GM lifters for a 2017 5.3L tahoe that I've given up and just come to realization that constant / intermittent misfire at idle is a bad lifter. Auction vehicle - Re-selling, so really only going to replace both intake/exhaust lifters on Cylinder 5 - but looking at rockauto I cannot determine if it's the long 4" lifter with the spring or the shorter lifter that looks like a shotgun shell.

would also like to have a new plastic valve lifter guide ready - just in case as plastic is brittle, but again I can't tell which lifter guide to purchase (other than the ones labeled "rear")

Thanks for any info you could provide as I'm kinda lost at this point

GM GENUINE 12740071 active lifter 4" with spring
GM GENUINE 12698945 LIFTERS ONLY; NON-ACTIVE FUEL MANAGEMENT LIFTER (shotgun shell size)
GM GENUINE 12669185 - is this the correct lifter guide?


Much appreciated.

 

[swathdiver]

Cylinder 5 is a conventional cylinder. Cylinders 1, 7, 4 and 6 are the AFM cylinders.

So you need 12698945 and the 12669185 guide. Check for bent pushrods and broken valve springs when you get it apart.