L94 to L96 engine swap

[davebarky]

Bolts right up, same manifolds, same heads, same intake, same flex plate, smaller injectors and 80 pounds added to the front end for the iron block. Tune it and go.

Use the Hummer motor mounts (25847739) while the engine is out and consider a billet torque converter with the improved Sonnax parts.

Thanks for confirming what I was thinking. At the risk of making this a bit more complicated, I was considering using a L9H cam, almost exactly the same as the L94, and my L94 injectors. I'm guessing that might get me to 380 HP or so and still allow regular gas. Just a thought. Do you know of a source for the billet converter? Most of them I've seen are pretty expensive. Thanks for the tip on the mounts, are they stronger than the stock L96 mounts? Any idea on what I should anticipate for fuel economy? I'll be saving a good bit with regular gas, but I'm not sure about relative fuel efficiency overall.

 

[donjetman]

Do you know of a source for the billet converter? Most of them I've seen are pretty expensive. T

https://cvcconverters.com/

 

[swathdiver]

Thanks for confirming what I was thinking. At the risk of making this a bit more complicated, I was considering using a L9H cam, almost exactly the same as the L94, and my L94 injectors. I'm guessing that might get me to 380 HP or so and still allow regular gas. Just a thought. Do you know of a source for the billet converter? Most of them I've seen are pretty expensive. Thanks for the tip on the mounts, are they stronger than the stock L96 mounts? Any idea on what I should anticipate for fuel economy? I'll be saving a good bit with regular gas, but I'm not sure about relative fuel efficiency overall.

The L9H camshaft is my way of thinking too. I would put new valve springs in the heads and probably new guides as the lift on the L9H camshaft is higher than the L96s.

Yes, the converters are pricey and cheap insurance in lieu of the original grenading and taking out the whole transmission which is creeping up to $6K these days for a GM reman installed at a dealer.

380 horse sounds about right. BlackBear can tune it for 87 octane and squeeze it for more power and transmission performance.

L96s are used on 2500 or larger chassis so I don't "think" the mounts will work on the 1500 frames.

 

[petethepug]

Shop for your L92 or L9H from a Silverado or GMC truck. The L9H carried on to 2010 in the trucks and not ludicrously priced like the full size SUV motors.

The L92 has smaller injectors and runs a two line set up to the motor from the pump. Except for the Escalade motors, the 07/08 L92 are detuned to 385hp.

The L9H is is identical to your L94 but it’s missing all the AFM hardware.

 

[davebarky]

Shop for your L92 or L9H from a Silverado or GMC truck. The L9H carried on to 2010 in the trucks and not ludicrously priced like the full size SUV motors.

The L92 has smaller injectors and runs a two line set up to the motor from the pump. Except for the Escalade motors, the 07/08 L92 are detuned to 385hp.

The L9H is is identical to your L94 but it’s missing all the AFM hardware.

That's what i was originally going to do and I've looked all over for them and can't find one at a decent price. The L9H would still be my first choice. It seems like everyone wants 4K or more. I can get a newer L96 for half of that. Then there's the question of durability. I spend a good bit of time at my brother's repair shop and we regularly see aluminum block LS engines with low oil pressure problems, etc. Most of the iron block engines don't seem to have these troubles and that's been my direct experience with my own trucks.

 

[Geotrash]

That's what i was originally going to do and I've looked all over for them and can't find one at a decent price. The L9H would still be my first choice. It seems like everyone wants 4K or more. I can get a newer L96 for half of that. Then there's the question of durability. I spend a good bit of time at my brother's repair shop and we regularly see aluminum block LS engines with low oil pressure problems, etc. Most of the iron block engines don't seem to have these troubles and that's been my direct experience with my own trucks.

I haven't seen that pattern play out here. Lots of folks here running iron block engines that have oil pressure problems that they solve with either a new sender and screen or a new pickup tube o-ring.

I have two aluminum 6.2's. An L92 and an L94 in 2007 and 2012 XL Denalis - 2007 and 2012, respectively. Had a low oil pressure problem when I bought the 2012 with 92K on it at the time that I solved with an oil pressure sender, and again after a cam swap that I solved by replacing the pickup tube o-ring. Other than that, they've both been trouble free. Lots of aluminum engines out there running around with 400K+ on them. I'd much rather have the 6.2 without AFM than a 6.0, and I tow a 7500 lb camper often so mine see heavy duty use. I always run premium fuel in both.

If it were my money, I'd pull that L94 out and give it a good garage rebuild with new pistons, Cam Motion stage 2 truck cam, oil pump, the works, and send the heads out to a machine shop to get cleaned up, then install BTR beehive springs and new valve stem seals. It'll cost you 2-3K in parts, but you'll have a beast of a runner when you're done and no more AFM to worry about.

If it would be helpful, you can post up a video of the sound you're hearing and we'll be happy to give it a listen. You can upload it to YouTube with public permissions and link it back here.

 

[davebarky]

Thanks for the input. A big part of my problem is that I'll be doing this in the shop and I'll have limited time. It's going to have to be a weekend engine replacement. I won't be able to tie up a bay in that shop for an extended period of time. The other aspect is that my wife uses this for normal day to day driving and occasional trips 600 miles away or so. It rarely sees 4000 RPM, she's not a pedal to the metal gal. I'm just looking for a quick and cheap way to get a reliable engine in this thing that has the kind of bottom end power she needs. I honestly probably won't even bother with a cam swap. The regular fuel thing is also a big consideration. I'll definitely hang on to the 6.2 and rebuild it, maybe even put it back in later. For now, she's driving her 2003 Suburban 2500 4x4 and enjoying the 13 MPG on regular gas. LOL.

 

[petethepug]

This time last year L9H we’re plentiful. Obviously everyone is keeping their vehicles longer. $3k for a 200k mi motor and $5k for 76k L9H motors seems to be the standard.

I’m paying attention now too. My only suggestion is to put the word out and tell the wreckers and shops you’ll buy em lunch or a 10 gal laundry bucket filled with their favorite bottle or can of beer and ice if they getcha a deal.

 

[davebarky]

I've pretty much exhausted the search for a reasonably priced L92 or L9H. At this point, I'm pretty sure I'm going to end up with an iron block 6.0. I'd like to eliminate AFM/DOD and keep the VVT. Aside from the L96, does anyone know which other engines will be compatible? I don't have a problem using my heads and intake, but I'd like to be sure that at least the bottom end will work without a bunch of headaches.

 

[Foggy]

I've pretty much exhausted the search for a reasonably priced L92 or L9H. At this point, I'm pretty sure I'm going to end up with an iron block 6.0. I'd like to eliminate AFM/DOD and keep the VVT. Aside from the L96, does anyone know which other engines will be compatible? I don't have a problem using my heads and intake, but I'd like to be sure that at least the bottom end will work without a bunch of headaches.

I'm not aware of 6.0's with VVT.. Maybe someone here will enlighten me. Many 6.0's don't
have AFM/DOD since they were put in the 2500's (even though the valley oil towers are there).
The 6.0 can be cheaper since there were tons produced. And would be fine. But if you
want to keep VVT you'll have to swap over timing components and cover/etc from your VVT motor.
IF i were going to a 6.0, I'd just skip the VVT altogether.. Yes it has it's advantages, but I
don't think you'll miss it. You'll just have to turn it off in the Tune (just like AFM)