H3 Alpha mods.

[Ghostbuster]

Hey guys, I had a 2009 CE for about 5 years and then decided to get a truck. Well I'm at a point where I can have both now so I found this 2009 H3x alpha in AZ, no rust just red dirt on it. It only has about 76k miles.

I've already rebuilt the front end, changed diff and t case fluids, and its currently at the body shop getting smoothed out before I wrap it 3M Satin dark grey. I'm going all out on this build and I'd really like to add more power.

The stock LH8 sounds very healthy, no noticeable bad noises. No obvious leaks besides a powersteering leak.

I'm intrigued by the L92 engine, no AFM or DOD cylinder deactivation stuff from an 2007-2008 Escalade. I could find a used one for around $3k and rebuild it a little before swapping it in.

Or I can try to put an LSA supercharger on the LH8 egnine. But I'd like to take the heads off and replace the lifters just in case. Maybe even get the heads refreshed a little.

And then there is the whole transmission issue. Should I try to get a strong 4L60e built or just go down the rabbit hole of swapping a 6L80e?

I plan on keeping this thing forever so I'm not scared of spending a lot of money, but still want to be reasonable.

Goals= 400-500hp and reliability.

Any advice is greatly appreciated.

 

[Doc Olds]

You can get 400HP (or so close it does not matter) reliably with your 5.3, no supercharger, no repeat Transmission replacements or T Case issues. I cam swapped my 09 Alpha off road, with our Air Doc Intake, a SuperModulation PP TB and SFan 4500 w/digital control, MagnaFlow Cat back and a hefty dose of HP tuner datalog analysis and tuning. Keeping it on Mickey Thompson Baja Legend MTZ 305s for now with stock 4:10 gears contemplating if I want to bother with 35s and 4:56s? Next up is a Trans rebuild with HD performance parts. I am pretty happy............. but am keeping my eye out for a sweet deal on a 6.2L if one falls in my lap.

Your swap to an 6.2 is going to take more work than you think and limiting that to an L92 might be a mistake. Look at an L9H in newer SUVs which still required the VVT delete just like the L92, which would all be taken care of with a cam swap anyways. Then there is always the LS3 without that issue as well, but getting harder to find in decent shape.

There are some guys here who have went the 6.0 and 6.2 installs, they can provide more details, like what monster TQ does in a FT 4X4 at WOT with the wheels turned.

Supercharges sound great, but not what I would do with this off road platform.

IMHO, you want fast/fun, get an old 2WD pickup for a 6.2 with killer trans and TQ converter project.

 

[Ghostbuster]

Thanks for the reply.

I don't want an agressive cam. Wouldn't that be necessary to get the HP up on the 5.3l?

So a 6.2l with a built 4l60e should be what I'm looking for?

Do I need VVT delete? Or just make sure it doesn't have AFM?

 

[Teahead]

If the motor is good w/low miles, just supercharge it.

Whipple or Magnuson.

 

[Doc Olds]

Thanks for the reply.

I don't want an agressive cam. Wouldn't that be necessary to get the HP up on the 5.3l?

So a 6.2l with a built 4l60e should be what I'm looking for?

Do I need VVT delete? Or just make sure it doesn't have AFM?

You would be building a truck motor, not a high RPM light weight car motor.

Use a truck cam with LS6 springs like I did, gain low & midrange HP/TQ with no loss of low end power. A low lift with a moderate increase in duration like 210-218 @ .050 range. I used a Texas Speed TSP Stage 2 Low Lift LS Truck Cam 212/218 .550"/.550" with 112 LSA. Hits that mark spot on. There are many other choices out there. 50+/- HP and a little less TQ at the wheels with no other mods except a tune for the cam. You end up with a barely noticeable cadence lope. If you want some chop, shorten the LSA to 111. More lift will bring more gains, but all at higher RPMs where these trucks do not go. For comparison, the stock LH8 has a lift of 190/191 degrees @ .050 with an LSA of 114 for getting kids to soccer practice.

Add the other goodies and tune accordingly for more.

You can get another bump with Intake Manifold (although the LH8 flows pretty darn good) with a FAST LSXRT Intake Manifold, again gains down low and all the way to the top. That is kind of pricey for 15HP. Want more, go with cathedral port heads - get real expensive there. Reminds me of the saying back in the day, the first 10 HP is cheap, after that the cost of poker rises exponentially.

I glossed over the details, but you can get the TSP Truck cam kit, with LS6 beehive springs, hat seals, crank bolt, gaskets for water pump, front cover, and cranks seal for like $530 delivered, better if you shop it for a while. All you need then is the 3 bolt cam conversion kit, including ARP bolts, LS3 chain tensioner, and HD timing chain just under $100. So all in $630 plus whatever you have to pay for your tune if you can't do it yourself. A SC complete kit is 8 -10 Xs that, more work and still needs a tune.

Looking for a replacement LS motor, make sure no AFM first and foremost. You can leave the VVT and stick the stock motor in, get the tune for that motor and good to go. I think that might be the exception, not the rule.

Most buy a 6/6.2 motor, then while it is on a stand, one thing leads to another.... like this thing has X miles, it needs this or that, before I install it. If a cam goes in that equation, the VVT is gone. That is what makes the LH8 a great LS motor, no AFM or VVT to mess with, just build away!

 

[Ghostbuster]

Ok, it sounds like I should just do the cam you suggested and be done with it for awhile.

Should I pop the heads off and do ls7 lifters and new trays and pushrods or leave all that alone?

And I should be able to just do the cam without pulling the engine right? just radiator and fan, water pump etc.?

Thanks for all the info I really appreciate it.

 

[H3Hummer]

nice job done to your truck.....and biiiiiiiig hugs to your Dog

 

[Doc Olds]

Ok, it sounds like I should just do the cam you suggested and be done with it for awhile.

Should I pop the heads off and do ls7 lifters and new trays and pushrods or leave all that alone?

And I should be able to just do the cam without pulling the engine right? just radiator and fan, water pump etc.?

Thanks for all the info I really appreciate it.

You do not need too pull the intake manifold or heads as you just upgrade the springs to LS6 springs. They can easily withstand .550 lift and the small increase in durations. They should last as long as the OEM springs do with the OEM cam. When you get aggressive with cam lift then spring become a maintenance item and may need to be replaced every 30-50K miles.

Yep, engine stays in the truck...

 

[Alpha X]

Next up is a Trans rebuild with HD performance parts.

I'd be curious what HD performance parts you're going with. I try to keep info like this handy in the event I should need a transmission rebuild.

 

[Doc Olds]

I'd be curious what HD performance parts you're going with. I try to keep info like this handy in the event I should need a transmission rebuild.

I have not 100% dialed that in yet, but for sure I will be using the Beast SunShell as they do not break, not the Sonnax SmartShell Heavy Duty Reaction Shell (which is still an improvement over OEM, but not as good). It will include some Sonnax stuff, just depends on the budget I decide for the project with input from my go to Trans guy.

To include:
Heavy duty wide band for maximum hold in 2nd and 4th gear with the Corvette servo instead of a Sonnax super servo.
For Fourth (OD) the Sonnax Dual Piston servo.

These are some great sources of info on that topic if you keep in mind they are Sonnax sales pitched as well:
4L60E Performance & Heavy-Duty Transmission Build Guides

Building the Killer 4L60E