Hello everyone,

Just heard about this site from a gmcsierra site I recently joined. I recently bought a 2012 Sierra 1500 SLE 4x4 z71 (not sure in what order I'm supposed to type all that lol) with about 117k miles. This is my first truck I've bought since a 1989 F150 I had while in the Marines. I'm just going to use the truck sporadically, mainly to haul some stuff as needed. I may take it on longer leisurely rides because I'm finding it much more interesting than my 2017 Santa Fe lol.

I have a ton of questions/plans for the truck but just reading this site for a few minutes broke my heart several times. I have a 2004 CTS-V sitting in my garage (been there for almost a year). I'm going to call a junk car place and get rid of it but will probably pull the LS6 engine out of it. The engine has about 145k miles on it but never gave me any issues that I remember. I was planning on either selling it (since I've heard it's relatively rare) or was hoping I could put it into the '12 Sierra. Guess the Gen III engine to Gen IV vehicle will require a ton of work though so that killed the LS6 dream. Plus not sure the LS6 would be ideal since it seems like it's more of a high revving engine.

Guess the best course of action will probably be to sell the LS6 and just modify the existing engine in the truck, buy the Summit Racing Gen III 5.3 450hp engine (if it will work in my truck), or try to get a junk yard/used Gen IV 5.3. Forgot to mention, I know basically nothing about this stuff lol. I've only done basic maintenance stuff on vehicles but always wanted to dive into engine rebuilding/swapping and performance upgrades. I have no idea what's been done performance wise to my truck already by previous owners so hopefully I'm not trying to upgrade a vehicle with redundant parts. Would love to get around 450 hp with a nice increase in torque, that would be my dream. Anyway, pic of the truck (I'm hoping the previous owner is a member so he/she can tell me what they've done lol):

 

sell the V, We have no idea what is wrong with it but I'm sure you could get more selling it than what a scrapper will give you

Don't bother swapping engines, just slap a supercharger on it and you'll be thrilled

 

yeah I’ll look into what I can get to sell it. Maybe I could at least get a few thousand from it.

would love a supercharger but not sure I want to go extreme like that especially on an engine with 117k miles. Although I’ve heard these 5.3 motors are really reliable

 

Whats wrong with the V?

Dollar for dollar it is hard to beat a supercharger. It won't be easy to get 450+ whp from a 5.3 without forced induction.

Read thru a bunch of build threads, it will help you understand how far your dollar will get you.

 

117k is fairly low miles, I'd leave the 5.3 mostly stock and turn up the boost.

 

Don`t let 117K worry you, I boosted my 5.3 at 100k and it now has 286k, boost it and enjoy.

 

i cammed my 5.3 @ 225k with no issues; 117k is nothing for a street LS engine.

 

I think the V would have to be considered a project vehicle at this point lol. It was okay before I left on a military deployment in '16. My wife at the time was supposed to look after it, start it on occasion, etc. Turned out she's a basket case. Left the car sitting for over a year and totally messed up my house. Anyway, had to do a bunch of maintenance to the car when I returned and cleaned then sold the house. The 6 sp manual can't get into 2nd gear, from what I've read it may be the synchro. Who knows what else is messed up the trans at this point though. There was a code that the car threw related to running lean/rich, can't remember now. I was trying to diagnose the issue from a Bluetooth car code reader I bought. Took the car to a mechanic and they couldn't figure it out either. Their answer was to ask me if the car was modded.

Superchargers are so expensive though. But damn I would love to have one.

286k with no major issues yet? I've never had a vehicle that long, that's super impressive.

Wow. Thanks for the info, you guys just made me feel a lot better about my purchase lol. This truck should last a LONG time then since it's not my daily driver although I'm finding myself taking it vs my boring SUV. Feels like I'm driving a military vehicle again when I'm in the truck. I think it's lifted a few inches but don't know how to tell for sure lol. Just bought two books on LS engines so can't wait to dive in. Well first I have to fix the nightmare trailer wiring issue.

 

holy rat's nest, batman!
and if the back end has blocks between the leaf springs & axle that are more than ~2", it's lifted. at the very least, the front looks leveled.

 

Those words are always followed by something bad