I don’t want 800HP. I don’t want a lopey cam or headers or a loud exhaust. I’m too old for that! It seems that older H2’s really needed another 150hp and a commensurate amount of torque in the right place. That said, it seems that the LQ4 is more than adequate for that task if built right.

As far as the trans goes, I’ve read about 4l70’s and 4l75’s that can handle a lot more torque. It seems almost plug and play since they are based on a 4l65e. Anyone have experience with these?

 

If it was me, I would drop in an LQ9 with a tow cam and a built 4L65e and a set of 4:56 gears.

It will drive just as stock but performance will be much improved,

Neal

 

I can say that on mine, adding full long tube headers, high flow cats, Borla stainless cat back exhaust along with a full tune up (new ACDelco plugs, wires, etc) that it realistically had plenty of power for the size vehicle.

 

Neal's suggestion would be a good one. For the most part the LQ9 is a higher compression version of the LQ4. They usually draw big bucks from the salvage yards and might have a ton of miles on them requiring a rebuild.

If you have a good condition LQ4 engine now it's a great candidate for a 30 over bore, 10:1 compression pistons, nice tow cam and your good to go, if you want a little more add an LQ9 intake an you will make about 75 more horses then the L92 that is used in the 08/09 H2's. Now do a level 4/5 rebuild/upgrade and add a custom tune to the ECU and your done! And it won't break the bank.

Swapping to a 4l75 is going to have issues too, GM changed a few things for the 4L70 series for one an input speed sensor plus other internal changes were made added to the 70 series and the transmission mapping is different in the ECU. I you wish to go this route make a quick call to Monster Transmission and ask their tech support.

Based on what you have said you and your wallet would be better with Level 4 or 5 built 4L65e and upgraded bullet proof LQ4. This way you have added value to your H2 for both you and if you decide to sell it down the road, many perspective buyers will pass on a heavily modded H2.

 

all good suggestions. I didn’t know the lq9 intake was different. It seems you trust monster transmission so I’ll call them and ask the best route for a 408. Then I’ll have to research cams and if to put different heads on. This will be my first LS build and it’s been 20 years since I built my last motor, a 396 small block stroker for a corvette.

 

If your doing the rebuild yourself I would build the LQ4 up to what you want,
The heads are good as is if only going to 500 HP range

Here's a link to my build for my 08

Neal

 

Looking around you can find the LQ9 in the 1500 to 2000 range with around 130000 miles on them.

Down side is you don't know the history on them of how they were taken care of.

Neal

 

link is not there

 

im wanting to build my own engine. The current lq4 is just fine at 100,000 miles

 

Sounds like a winner and a good safe bet, you know what you already have and its condition. I guess if you wanted more then 500hp you could always dump LS3 heads on it but that would force and intake manifold change too.