LQ9/LQ4

[mobileaudio25]

lq9 is higher compression but harder to find, only came in escalades, H2's, denali's.
lq4 came in box vans, railroad service trucks, you name it. Came in long crank iron headed versions also.

lq9 all have gen 4 rods which are ~850hp safe
lq4 can have gen 3 which are ~650hp safe, or the gen4 if its 03/04ish or up.

Both can handle 1000hp stock but it depends on how bad you want to drive over your rods at 130mph. If you aren't going to have a 10.0 cage and run a 275 MT ET Pro all the time a gen 3 is fine totally stock. The chance of hooking a 850hp stock bottom lq9 and blowing the rods out the side and not already dumping 10G of chassis work in to handle it is low. By the time the car can handle 850hp your going to have enough money in tripple 450 fuel pumps, cage, bump boxes, boost controllers, and other stuff that you will have put rods and pistons in long ago.

Buy a 03 2500 work truck lq4 and 80e, pull drivetrain out, drop it in G body. Savannah van works too.

Most lq9's had an AWD 60e. 80e really didnt come come in until 2500's and vans and the lq4 was what you got there. Im sure GM bolted 2wd lq9 to 4l80e but its going to be like finding hens teeth.

Buy engine, swap cam and valve springs, and call it fine. Bonus is if you get a 150k mile one the rings are pre gapped for boost 🙂 Basically the rods fail well before the rod bolts do, cranks don't flex until 1300hp+, and putting head studs doesnt do much because the decks flex due to thickness or they push water due to agressive timing and bend rods long before the heads lift due to poor clamp load.

I like you haha. Lots of good info there thanks. I didn’t know that an 80e ever came behind a lq4. That would be ideal and make my setup a little more plug and play. I’m definitely looking to boost so I’m going to get the lq4 for sure.

I didn’t realize that the only difference between the two were just compression. If I wouldn’t know that I wouldn’t have been looking for a good LQ9 so hard..

 

[mobileaudio25]

How much power are you looking to make? Some folks are making 800 - 1000 whp on a stock gen 4 bottom end. Reliability may be an issue at that level.......but if your goal is closer to 5-600 whp.... I would get a good, low mile, stock 04-06 motor, re-gap the rings....and save the money you would have otherwise spent at the machine shop, on rods/pistols, etc.

You’re saying try to get away without having to do any machine work and slap and new set of rods, rings, pistons cam, maybe the valve springs and mains? I just want 500+ to the wheels. I can tweak and swap the heads cam ect a little down the road if I feel the need to. I like boost because you can play with power a little more

 

[87National]

You’re saying try to get away without having to do any machine work and slap and new set of rods, rings, pistons cam, maybe the valve springs and mains? I just want 500+ to the wheels. I can tweak and swap the heads cam ect a little down the road if I feel the need to. I like boost because you can play with power a little more

Yes, get PAC valve springs, open up the ring gap a little. You can make 500whp on the stock cam, but it wouldn't be a bad idea to get an ls6 cam or the "sloppy stage 2" cam. You can easily meet your 500whp goal with a 4.8 or 5.3 if you want to save a little more over a 6.0.

 

[Injectedcutty]

Yes, get PAC valve springs, open up the ring gap a little. You can make 500whp on the stock cam, but it wouldn't be a bad idea to get an ls6 cam or the "sloppy stage 2" cam. You can easily meet your 500whp goal with a 4.8 or 5.3 if you want to save a little more over a 6.0.

That's the plan with the 5.3 I'm building. I had the stock 862 heads worked, added BTR .660 springs to support the Tick stage 1 turbo cam(.613/.598 lift), trunnion upgrade, BTR pushrods, Holley Mid Rise intake. Going with twin GT35's(chinese turbo's for now). Should easily make 500rwhp on low boost, and I might get a 6.0L block and build it up to a 408 and swap it down the road....

 

[motorheadmike]

Ol' Quagmire 1.0 will probably put down 500 to the wheels on reworked stock junk too. It just looks less pretty and the specs aren't as impressive on paper. Find your cat and skin it.

 

[mobileaudio25]

Yes, get PAC valve springs, open up the ring gap a little. You can make 500whp on the stock cam, but it wouldn't be a bad idea to get an ls6 cam or the "sloppy stage 2" cam. You can easily meet your 500whp goal with a 4.8 or 5.3 if you want to save a little more over a 6.0.

I’d like to go the with 6.0. I’ve been reading up more on the lq4 and I’m going to go that route.

4l80e boot right up to a lq4 so I won’t have to change the flexplate or do any modification for the transmission to bolt up

 

[mobileaudio25]

Will the lq4 bolt right up to any 4L80e without any modifications? I’m definitely going to run a 4l80e that way I have room for future upgrades.

Is it harder to mate a separate 4l80e with a different motor than it came with or will flashing the computer take care of the mismatch ?

 

[Turbolq4]

Will the lq4 bolt right up to any 4L80e without any modifications? I’m definitely going to run a 4l80e that way I have room for future upgrades.

Is it harder to mate a separate 4l80e with a different motor than it came with or will flashing the computer take care of the mismatch ?

4l80e is pretty much the only trans that came behind an LQ4. There were very rare manual trans trucks, no 4l60e came with them. If you have a harness that originally came out of a vehicle that had a 60e then you have to repin the connector and change the trans in the factory ecm but the actual connector itself is the same for both transmissions.

I suggest installing a transgo2 kit in the 80e. Not too difficult, trans shifts nice, and is capable of living behind boosted high torque engines.

 

[87National]

Damn that looks nice. Wish I had the patience and attention to detail pull that off. On every motor swap I've ever done.....I just toss the greasy, rusty motor in as-is without any thoughts towards aesthetics.

That's the plan with the 5.3 I'm building. I had the stock 862 heads worked, added BTR .660 springs to support the Tick stage 1 turbo cam(.613/.598 lift), trunnion upgrade, BTR pushrods, Holley Mid Rise intake. Going with twin GT35's(chinese turbo's for now). Should easily make 500rwhp on low boost, and I might get a 6.0L block and build it up to a 408 and swap it down the road....View attachment 80400

 

[mobileaudio25]

4l80e is pretty much the only trans that came behind an LQ4. There were very rare manual trans trucks, no 4l60e came with them. If you have a harness that originally came out of a vehicle that had a 60e then you have to repin the connector and change the trans in the factory ecm but the actual connector itself is the same for both transmissions.

I suggest installing a transgo2 kit in the 80e. Not too difficult, trans shifts nice, and is capable of living behind boosted high torque engines.

So if I found a good running lq4 without the attached transmission it’s pretty safe to assume another good running 80e can plug and go right with it without any extras needed?

I like the idea of finding a good running transmission and adding that kit and not have to do a complete rebuild and I should be safe to 500-550 whp