Hi yaI bought a 2012 used Silverado in late 2012, smoking deal. I used it to tow a 19-ft travel trailer, then I hauled an Arctic cat wildcat trail in the bed with tailgate down. I had to use a long receiver extension.
Driving from Phoenix to the mountains in Flagstaff the truck would drop down to second gear and just scream up the mountains.

I needed more power.
So I installed it LSA supercharger on the stock 5.3 with methanol injection. This work fine for several years until a long trip to Seattle. One day while gassing up I found the truck was 4 quarts low on oil. The truck would not use oil powering up mountains. But it would pump oil going down the mountains with engine breaking, The rings were shot. The engine still ran fine but I needed more.

So I picked up a used LY6 engine, had it machined. Lowered compression to 9.6 to 1 forged pistons and rods, Head studs. Reinstall the LSA supercharger and methanol kit with headers making about 13 psi of boost.

I had a local shop Dyno Tune the truck. It absolutely screams over 3,000 RPM but everything under that is just rough. I did a test tow up to sunset point and the engine oil temperature reached 278°.

There was no time to address this before vacation so I bought a 2003 3500 dually, but that's a whole new story.

Recently I added a external engine oil cooler with thermostat to control oil temperature.

Black bear performance tuned the 5.3 and began with the LY6 but quickly became unresponsive for updates I don't blame them because I stretched it out over so many years. And then I spent a bunch of money on the local shop for tuning.

And thankfully thanks to this forum I was able to find Nic D. I'm hoping this will be the last time I have to tune this truck. I need to save my pennies for the 6L80 upgrades.

Apparently I have been on this form for a while but never introduced myself.

I do need to find a bigger reservoir for the supercharger intercooler all suggestions would be welcome.

PFA my Tow pig and travel trailer

The LSA on the Ole 5.3:

the old engine

The new camper

 

I shouldn’t ask this in intro section, but do you know what camshaft the guys put in the LY6? I’m asking this because with the right camshaft and the LSA blower, this rig should be a torque monster. You use the heads off of the 5.3, or the 6.0? You could go either way with adaptors for the supercharger.

 

This was the first game I put in it
Comp cam 54-702-11
226/237 duration at .050
113° LSA
663/638 lift
The tuner said it was too big for my stock converter so I swapped it out for a stock LS9 camshaft.

Turns out it was not the cam it was the tune.

I'm using the stock LY6 heads. So I did not need the rectangle port adapter that I did use on the 5.3.

Again the tuner blamed the hardware stating the rectangle port adapters was causing pooling resulting in the off idle stumble. That too was a tuner issue.

This thing is a torque monster. It has over 300 pounds of torque before 2000 RPM. When it rains I have to drive home in four-wheel drive just to get traction.

 

As it should be. Sounds like you’ve got it sorted out.

 

Hopefully Nic D can polish up the tune soon.