Considering an LS in my GMC - I have a few questions

[CC69Rat]

Let me first say, I have owned a couple Trans Ams, a 1LE Z28, etc. I know the performance of the LS based motors and what they are capable of.

I'm completely new to the codes, year models, etc. I am doing research now .. I just want to ask for differences in opinion. What's the best one to get for overall ease of building, avoiding extra expense for wiring issues, etc. Ex. Find a 2005-2007 Escalade and get .. these parts.

SSR ? GTO ? They're probably all pretty nice in the end, .. but what am I looking for? I'm thinking I'd like to have a GTO swap for the transmission?

Your thoughts please? My truck will be setup with a LOT of suspension goodies, 4 wheel discs, etc. I just need some more HP and reliability, mpg and crap-a-nol compatibility.

Thanks.

[Clyde65]

I would speak to someone like Turnkey Engine Supply. they can configure and sell you an LS based motor and trans with all the goodies and go fast stuff you want, so it would be drop in and go, kinda turnkey.

[theastronaut]

What exactly are you looking for? Iron or Aluminum block? HP? I'll be doing an LS swap in my '66 and haven't completely nailed down which one to go with either. I'm leaning towards just building from scratch starting with an aluminum LS2 block.


Some that I've considered. I'm no expert on LSx engines, so correct me if I'm wrong about any of this!!

L33- Aluminum block 5.3 from extended cab or 4 door 4WD trucks. About 320hp stock, head castings similar to LS6 (405hp Z06 engine), and a cam change with bolt ons and a tune makes over 400 hp. Probably your cheapest aluminum block option. Smaller displacement is better for mileage too.

LS2- GT0, SSR, TBSS. Aluminum block, 400 hp/400 tq stock. Easy to find a takeout with a 6 speed. Much higher cost, modded L33 could be about half the cost?

LQ4/LQ9- Iron block 6.0, around 300/345 hp stock. Main difference is LQ9 is higher compression. Alot of potential, 500 whp is quite doable with the right parts.

Iron blocks are around 100 pounds heavier- you mentioned suspension work and an extra ~100 pounds over the front axle may not be wanted if you're going to autocross it or drive it competitively? If you go with a T56 they have a .60 sixth gear so you'll need at least a 4.56 R&P (depending on your tire height) if you ever want to get into sixth gear on the interstate without lugging the engine. With 29" tall tires 2000 rpm works out to something like 76 mph with a 4.56.