Jscm3

Hi, I posted this in another forum without results, so I'm hoping it's more appropriate here


I recently bought a nice, low mileage 5.3 9-7x (Envoy, Trailblazer) suv that soon developed a pretty severe rod knock. Best I can tell, my wife drove it about 8 miles home that way. I fully intend to rebuild the short block, also eliminating the AFM, however fearing the worst (cam or crank bearing issues), I started researching my options.

LH6 cores around here are crazy money, nobody seems to sell short blocks, and I would hate to spend all the money on a long block (don't need heads) only to replace the cam & dod lifters thus voiding any warranty.

I even though my LH6 is a gen IV, I believe this configuration has a 24x crank. A L33 is a 24x, aluminum block, same heads, no AFM, but a gen3.

Could I just swap cam gears, use my front cover w/ cam sensor & mount the knock sensors on the side like the gen IV? I do realize I would have to have the AFM tuned out of the PCM.

I'm hoping this is all theoretical, & I can just repair my motor (24k miles), & install a DOD delete. But if not, any reason this would not work? Is there any downside to converting to a GEN3?

Thanks for any advice you can provide

MuhThugga

You'll need to drill and tap the sides of the block for the knock sensors, or use an M10 - M8 step stud in an unused M10x1.5 bolt hole.

Otherwise, you should be good to go with swapping the rest of the Gen IV components over so long as the current engine is already 24x.

Jscm3

Thanks, that's very helpful.
I assume it would still have the boss at the correct location that needs to be drilled & tapped?

MuhThugga

I don't know off the top of my head if any boss is in that location on the Gen III blocks.