Been watching too much Roadkill lately, but it has me thinking about what I can do to get some more umph out of my 5.3 Z71 4x4 Silverado.
Truck has 156k and runs great. It does suffer from the AFM oil loss, so that needs addressed.
Reading info on the truck forums makes my head hurt, so I thought I’d ask you 5.3 addicts here.
What is the best upgrade path to make a daily driver more fun? I’m open to all suggestions. Will the truck being 4x4 change anything?
I'd start with a cold air induction(airaid,K&N), headers, cat back exhaust, and a tune. Need any aspirin yet?
I'd stick with the normal stuff like NRNG said. That will give a wee bit of extra, but not anything really major.
Another option is to pony up $1500 or so and find an LQ9 6.0L from another truck. Escalades are a good source. The only real difference between the LQ4 6.0 and LQ9 6.0 is the piston. LQ4 has dished for 9.5:1, LQ9 has flat tops for 10:1 They both should have the really good heads that are basically identical to the LS6 but with slightly bigger chambers. Casting numbers are eluding me right now but I think the LS6 head is a 243 casting.
Anyway, an LQ9 makes 345hp out of the box and uses the same computer as your 5.3 with a different tune. Swap out engines, plug it in, flash, and you're in business.
I bought an LQ9 for a project that came out of a front-end wreck Escalade and the accessories had all been squished. It had 60k on it and was $1300 because it didn't have the brackets and the only accessory that survived was the alternator. Since you have all the things already, you might be able to find a longblock for $1000, swap over intake and stuff, and sell your 5.3 longblock for $600 making the project a lot cheaper.
Headers and exhaust in all honesty if you don't plan on doing much with it. You can do CAI, but don't pay an arm and a leg since your best bet is a big tube and a cone filter.
Tune wise, just get an off-the-shelf tune like a Diablo handheld or something. Plenty of tunes to copy with such mild builds like yours.
If you get bored with it and want it faster for "cheap", hit up the Sloppy Mechanics wiki and go from there.
If you are having AFM issues, why not do a delete kit with a hotter cam?
Tom_Spangler said:If you are having AFM issues, why not do a delete kit with a hotter cam?
This. The 5.3L camshaft is absolutely miniscule, like 196 degrees of duration. Delete all that, slip in a lightly bigger cam, then reflash the ECM with HP Tuners (the Silverado ECM lets you really get away with some silly stuff if I recall.) Cam swaps are one of the easiest ways to pick up big power on an LS
Blackbear tune! Or yes, cam it.
NickD said:Tom_Spangler said:If you are having AFM issues, why not do a delete kit with a hotter cam?
This. The 5.3L camshaft is absolutely miniscule, like 196 degrees of duration. Delete all that, slip in a lightly bigger cam, then reflash the ECM with HP Tuners (the Silverado ECM lets you really get away with some silly stuff if I recall.) Cam swaps are one of the easiest ways to pick up big power on an LS
I agree for the most part. Head flows and compression can pretty easily support more cam in LS motors, but the 5.3 being a little light on displacement won't want much cam in a heavy truck. A really mild bump in cam would be OK but anything more than mild would need a higher stall or you'll complain about low end torque.
Your truck probably has 243 heads already. They started putting those and the 799s (same head) on the newer 5.3s and 4.8s, dont knoe the year they switched but i bet an 07 has them.
Id do lt headers, they make a prettt big difference on ls motors, a cai, a tune and maybe an intake. If the tbsd intake is a decent upgrade id go that route, not a fan of the fast alternatives.
Id bet that give you a pretty big improvement, if you want more then slap a cam in it. IIRC the ls6 is a super cheap popular alternative, but most of the ls speed shops have off the shelf grinds made for trucks and stock converters.
Wait i misspoke, just put a cheap on3 kit on, a local has a 4.8 with that kit said outside of tune and fueling it was pretty complete, makes around 460whp.
You should look into Sloppy Mechanics. 
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