LQ9 or 5.3 build advice
Thread Starter
On The Tree
Joined: Nov 2020
Posts: 136
Likes: 7
Looks like the more cost effective for me might be to purchase a complete vehicle for the swap. Do most of the cars with Lq4/9 come with a transmission that will hold up also or is there some engine and transmission combos to stay away from?
3/4 and 1 ton vehicles will come with a 4l80e
1/2 tons the 4l60e
the 80 is a lot more heavy duty, but eats more power to turn. These are usually best served for power adder applications.
Newer trucks will have a 6l80, given your usage this is probably the one to hold out for. The extra gears, and ratios it provides will maximize the power put to the ground from a mostly stock engine
the newest trucks will have 8 or 10 speed trans. These are going to be pricey, and probably not the best option. They will be mated to direct injection engines. Also the early versions of these are known to be problematic. They are good, but have had a lot of changes (revisions) so a crapshoot of what you end up with.
1/2 tons the 4l60e
the 80 is a lot more heavy duty, but eats more power to turn. These are usually best served for power adder applications.
Newer trucks will have a 6l80, given your usage this is probably the one to hold out for. The extra gears, and ratios it provides will maximize the power put to the ground from a mostly stock engine
the newest trucks will have 8 or 10 speed trans. These are going to be pricey, and probably not the best option. They will be mated to direct injection engines. Also the early versions of these are known to be problematic. They are good, but have had a lot of changes (revisions) so a crapshoot of what you end up with.
Last edited by bthomas; Dec 14, 2023 at 08:21 AM.
TECH Fanatic
Joined: May 2016
Posts: 1,292
Likes: 436
From: St. Louis
There is absolutely nothing wrong with the 4L60E, It's the same internally as a 700R4. I see guys at the local track (wwtr) making 9-second passes on these transmissions all the time, I've drag raced them with great success and I autocross another car with one. Guess what? The trans that I race autocross with has 230,000 mi on it and it still shifts like it's brand new, originally an LS1 but now its had a 11.9:1cr 6.2L in front of it for 4 years now still going strong. I have a suburban, a 2004, It has 320,000 mi on it, original 4L60E still shifts like it's brand new. If you get a wrecked running vehicle most likely the trans will be fine. The biggest problem with these transmissions is getting them rebuilt by someone who knows what they're doing.
Being that thr LQ9 was the foundation for the LS2.. Having the exact same flat top pistons, floating vs pressed (like the LQ4 that also has dished pistons).. Either find some 799s and make an iron block LS2 or rect port heads and make your own mild cam version of the GM crate LS364. I'm doing that with for my LS swap in my 85z28-iroc (but bigger cam cuz no smog in FL and to match my 3500 tci stall) and 6L swap for my 04 Tahoe. Both getting 823's heads (ported by me) that I'm swapping the solid intake valves out for the hollow stem LS3 valves got for cheap as were used take-offs I got from ebay. And since both being na builds, why not lol... But I would swap it in the Z28. That way you have something fun you can race with still. Even a mild cam with a 6L and rext port heads can hit 440whp in a t56 car. The LS364 crate engine usea the 02-04 Z06 cam and GM has it rated a 452hp. I think that's a bit conservative. Even if you use the SDPC LS6 Power Max Plus cam (220/222 duration .570/.570 lift on a 112+2 LSA), it should put the 6L around 480hp flywheel range. With a ported factory LS3 intake mani or a FAST LSXR intake and tb and best flowing exhaust you can get away it (long tubes of course) and port the 823s a tad, probably get closer to 500 flywheel hp.
Good luck!
Good luck!
Thread Starter
On The Tree
Joined: Nov 2020
Posts: 136
Likes: 7
I have been checking marketplace and seen early 2000 suburban/tahoes for about 2k for the complete car, while the escalades are about 3-4k here in socal. Are early 5.3's a good bases for a swap incase the lq's prices stay high?
