BigEd_72455

iTrader: (7)

Which one do I actually have?? Gen 3 or Gen 4?

Aluminum block, 5.3L, rear cam sensor, gen 4 rods, gen 4 head bolts, 24x crank.

Pics attached...

Sodak66

Gen III

BigEd_72455

iTrader: (7)

can you explain or are you guessing?

psicko

If you're ordering head bolts, it's a Gen IV. If you're ordering a cam, crank, or knock sensors, it's a Gen III. If you just want to know what to call it so you can sleep better at night, it's a gen 3.5.

BigEd_72455

iTrader: (7)

I really need a definitive answer of 3 or 4 and the date code explained.

Reason being is Darton does not make sleeves for a Gen3 anymore (discontinued), but they do a Gen IV.

I can't tell what difference it would make when sleeving a block, but apparently something is different.

Sodak66

For that purpose its a Gen III block. No we are not guessing its very easy to tell from looking at it. A quick google search would give you all the info you need. good luck with your build.

psicko

Steve @ Race Engine Development would be the guy you need to talk to in that regard.

G Atsma

The valley knock sensor location is the dead giveaway here. NO Gen IV's came that way. Gen III it is....

RonSSNova

iTrader: (3)

That is an L33. 05-07

There was an LM4 alum engine from that era that was pure gen 3 with the longer head bolts. It was otherwise identical to its iron counterpart the LM7

GM did odd combos before switching to the Gen 4 in 2008 I believe.