This has perhaps been beaten to death, but I have searched, trust me I have.

I found a good deal, a LC9 engine for $400 that the owner claims he had replaced and I quote "I have a 2008 GMC Yucon 1500 XL SLT 5.3L Engine for parts or rebuild. This Engine has a 214000 mile and has some problem. replaced with another engine and this one can be rebuild. here is the exact problem for this engine from my mechanic. "2008 5.3 with fuel active management. #4 cylinder has a low compression by 30 psi lower. Causing rough idle. Flat cam on #4?" I am not a mechanic and I cant answer any technical Questions. if you are interested you can contact me. I can not deliver the engine. it will be a buyers responsibility to pick it up. the engine located at Interstate I70 and Quebec.
PS: Vin 8 is 3 NO OTHER ACCESSORIES ONLY ENGINE.
$700.00 OBO. Thank you for your Business.
do NOT contact me with unsolicited services o"

Before this I was going to buy a EXT aluminum engine for $600 but the seller seems lazy and unwilling to communicate, so I decided to pursue elsewhere which led to this. I am no stranger to building engined or working on cars, so I can tackle the rebuild, but I am have more of a PHD in rotary engines to be honest. I have done some head braking research on the matter, I know tat DOD (displacement on demand) might have so culprit in the matter of low compression. Are these LC9 engines a good platform? and I ask because I wish to swap some ls goodies here and there. I like the lower displacement 5.3 since this car is going to be oriented towards auto-x and track, thus my pursue of the Al block.
I plan on running full standalone and removing the VVT or DOD system in favor of all eight always engaged. I wish to remove the throttle by wire and have cable like the good ol' cars and mate it to a T56

Any thought kindly appreciated

 

They're good sturdy blocks. I've got one myself that I had planned to use until I got a deal on an LS2 block.

It has the same stroke as the 5.7L-6.2L engines, but the smaller bore to give it 5.3L, so you're limited in cylinder head choices. They can be bored out so that you could use LS1 pistons and make a 5.7L out of it.

 

Remember with a truck motor you need a different oil pan, water pump to clear the TB cam, accessories and harmonic balancer. Plus the intake won't clear the hood. That's about $1k parts unless you get crazy deals.

Vvt/DOD delete is also another $1k+ once you factor in a better cam.

If you plan to track it get the alum block. An Accusump and/or oil pan baffle from improved racing should also be on the list.

 

I did factor all those goodies in, not to the tee but did consider the basics. Now I am somewhat concerned about the VVT DOD setup though I don't want this to go over budget to fast, although that always happens. It seems like such a good deal though for a complete Al longblock. Where every else seems to want at least $1400 for a l33 or similar Al engine this one is only $400, and perhaps $300 if I can talk him in to it. Now I can't really shell out $1500-$2000 for an LS1 engine in one large sump since it would put a blister on my finances. I'd rather slowly build it upon funds becoming available. Even if I went w/ a ls1 engine I'd still be looking at doing some upgrades as far as cams go.

It seems like a good route for the budged minded, and that's a lie I am willing to live with I don't want to sacrifice reliability, power I can do with out worries and with 320hp on tap I shouldn't be bad in that regard either.

That's the reason I turned my back on the rotary (for now?) since it's time consuming and costly engine building and part sourcing process that frankly I just got tired of opening a 13B-REW's only to find out that the apex seals got wedged so badly trying to exit through the exhaust port it put deep mark on the rotor and housing that now they only work as a desk ornament and conversation peace.

I am a little concerned however on the 58x reluctor wheel as it seems limited in options.