Drivetrain Advice

A long time ago I started working on a Wide open Design Tube Chassis CJ project. I built a set of Chevy 1 Ton Axles up with all the goodies and then purchased a wake boat. The boat took all my time and money for five years. 2 years ago it burned up in a storage unit fire along with my old CJ I had owned for 30 years. Recently I decided to start building the chassis again. I bought a rig to wheel while I finish it and it has helped motivate me even more. I need to put a drivetrain together and am ready to order. I placed an order for an atlas with the best stuff they have to use earlier this week and have been reading all I can about TH400s. does anyone have any experience with any of the vendors that build the high end 400s? Im thinking Reid case, reverse Manual valve body with engine braking. What about lower gear ratios? Pros or cons? I have never owned an automatic Jeep or truck before this one I just bought. I like it a lot but know little about them and read about so many bad experiences with shops that I am pretty nervous to order.

For the engine I have been thinking just order a GM Crate LS whatever number they are now. I don't think I want to deal with a rebuild. I hear it's hard to find a good engine machine shop these days. What is preferable for a Jeep aluminum or Iron? My Boat had a LSA and I absolutely loved it but I don't think a boosted engine would be a good Idea for a Jeep for several reasons. . Am I wrong? I do want between 5 and 6 hundred HP.

Thanks in advance for any advice.

bobs-new-cj-build-thread.110968

The thread I started years ago.

Are you looking for a local shop for the th400? If you’re looking for an online vendor I’d hit up monster transmission, Randy’s transmission, or Hughes transmission. They all are very familiar with what the off road community want out of their rigs trans. I’ve personally dealt with Hughes with my last rig and I’ll be using them again for my new build. Wasn’t a full trans build, just parts for it, but a good sales and tech team.

For a motor it depends on few things like funds, availability, and end goal. If you’re wanting to keep it light then yea an aluminum block would be the go to. If you’re wanting to boost it the usual go to is the iron blocks.

Here’s a good site for ls info

_Auzzy_ said:

Are you looking for a local shop for the th400? If you’re looking for an online vendor I’d hit up monster transmission, Randy’s transmission, or Hughes transmission. They all are very familiar with what the off road community want out of their rigs trans. For a motor it depends on few things like funds, availability, and end goal. If you’re wanting to keep it light then yea an aluminum block would be the go to. If you’re wanting to boost it the usual go to is the iron blocks.

Here’s a good site for ls info

The Definitive Guide to LS Engine Specs and LS Engine Upgrades

We put everything you need to know about the Gen. III & Gen. IV LS engine family in 1 spot—from cam specs to upgrades & everything in between.

www.onallcylinders.com

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Thanks for the recommendations I'll look into those shops. Jakes and Maximum Transmissions also come up as build shops. Im not against a local shop but it's not a requirement. Might be nice if there are issues though.

bobdog said:

Thanks for the recommendations I'll look into those shops. Jakes and Maximum Transmissions also come up as build shops. Im not against a local shop but it's not a requirement. Might be nice if there are issues though.

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Maximum is a good one too, never looked into Jake’s though. But local does have that benefit of helping out if ya have issues. Like for example some super smart guy measures his output shaft wrong and has to send his trans back to have the proper shaft installed after he got the trans installed and couldn’t figure out why his tcase outputs wouldn’t spin.

For a TH400 Id just order a FTI or even a TCI right from Summit. Easy peasy.
Jakes stuff is top notch for sure but a good 400 can be had pretty easy these days.

500hp isnt super tough with a decent LS but it will have a decent sized cam and may make power up a little higher rpm than you want in a crawler.

Summit sells a 450hp 5.3 longblock for like $3500 thats hard to beat these days.
I think ATK does the builds but price / HP is hard to beat for soeting fresh in a box.

427ci-proseries-stroker-crate-engine-gm-ls3-style-dressed-longblock-with-fuel-injection-aluminum-heads-roller-cam-psls4272ctf

I wonder how something like this would work in the lower RPM range. The chart they show doesn't start until 3000

239/250 @ .050 isnt gonna make any power under 3000.
under 200 @ .050 is what you want for slow going but it isnt gonna make 500hp.

That is a BADASS motor and would be a riot with a 4500 stall converter but not a real crawler friendly deal.

NYCEGUY01 said:

239/250 @ .050 isnt gonna make any power under 3000.
under 200 @ .050 is what you want for slow going but it isnt gonna make 500hp.

That is a BADASS motor and would be a riot with a 4500 stall converter but not a real crawler friendly deal.

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They recommend a 2200

It’s making almost 500 lb/ft at 3000. I’m curious what it does at 1500

Sorry to hear about the boat & CJ fire Bob, that's terrible! Hopefully insurance helped ease the loss.

I've had a good deal of experience with LS engines, driving 6.0 powered trucks, building aluminum block engines and now owning a LS3 crate engine with a hot cam making 500 HP. The aluminum block will save you 150#'s and IMO that's not really significant in a crawler. You're going to spend way more for that 150#'s. With high HP (350+) and high compression, you now get to deal with managing additional heat & noise and that takes a lot of effort, I've been dealing with it in my TJ.

I love my LS3, but it's simply overkill and makes very technical crawling a bit more challenging, IMO. Mine needs some additional tuning to perform better down low. If I had the choice, I'd rather have a L92 truck engine (2007-2008 Iron block 6.0, Gen 4, 58 tooth reluctor, square port heads, TBSS intake) with an aftermarket mild cam. That's an engine that will make gobs of torque, still rev high when you need it and be perfect for a crawler.

I've had Cleggs in Orem do the machine work on a LQ4 engine, they're awesome, have a great track record and know what they're doing. - https://www.rme4x4.com/threads/gm-lq4-rebuild.118286/

If you're set on a crate engine, I like this one... that's the truck TBSS intake that makes gobs of torque down low, but still revs high. It's the best factory intake for both torque and power up high. - https://blueprintengines.com/collec...-l92-aluminum-heads-roller-cam-6-2l-longblock

Greg said:

Sorry to hear about the boat & CJ fire Bob, that's terrible! Hopefully insurance helped ease the loss.

I've had a good deal of experience with LS engines, driving 6.0 powered trucks, building aluminum block engines and now owning a LS3 crate engine with a hot cam making 500 HP. The aluminum block will save you 150#'s and IMO that's not really significant in a crawler. You're going to spend way more for that 150#'s. With high HP (350+) and high compression, you now get to deal with managing additional heat & noise and that takes a lot of effort, I've been dealing with it in my TJ.

I love my LS3, but it's simply overkill and makes very technical crawling a bit more challenging, IMO. Mine needs some additional tuning to perform better down low. If I had the choice, I'd rather have a L92 truck engine (2007-2008 Iron block 6.0, Gen 4, 58 tooth reluctor, square port heads, TBSS intake) with an aftermarket mild cam. That's an engine that will make gobs of torque, still rev high when you need it and be perfect for a crawler.

I've had Cleggs in Orem do the machine work on a LQ4 engine, they're awesome, have a great track record and know what they're doing. - https://www.rme4x4.com/threads/gm-lq4-rebuild.118286/

If you're set on a crate engine, I like this one... that's the truck TBSS intake that makes gobs of torque down low, but still revs high. It's the best factory intake for both torque and power up high. - https://blueprintengines.com/collec...-l92-aluminum-heads-roller-cam-6-2l-longblock

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The YJ I just bought has an LQ4 but it has a car intake and is controlled by a Holly Terminator system. It runs great a lot of power and runs between 180 and 200. I like it a lot. But.... I want more for this project. I like the idea of a stroker and with transmissions running 10,000 and TCs 5000, 17000 doesn't seem quite as crazy. This is end game. Im older and not ever doing this again.

The 560 HP LSA in my boat pulled like crazy down low. I wonder how hot it would run.

bobdog said:

The 560 HP LSA in my boat pulled like crazy down low. I wonder how hot it would run.

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The little LSA blowers are great. lot of power down low and its instant. I woudnt think it would run any hotter than any other LS but you do have an additional heat exchanger/radiator just for the intercooler.

My C10 has a vortech centrifical on its LS and I like it a bunch. It makes good power but you have to wind it up a little. In a little hot rod truck with a lose converter its awesome. Its only pushing 6-9 pounds of boost and not even intercooled.

That said after my Blazer is running I have a little Silverado Im also working on and I have a LSA setup on the shelf for that..
Its getting a fresh LS2 bottom end I built with CNC ported LS3 heads and a decent sized cam speced for a PD Blower.
Should be a riot...
Ill start a thread on that project once the Blazer is running...

Thoughts??

Seems like a super cool motor AND the absolute most expensive way possible to get 400hp..LOL

Maybe I could live with a 6L80? Not my first choice but

Probably not availabe

If you go 6l80 get a good converter. The Automative Transmission Rebuilders Association (ATRA) has a lot of evidence and an article linking most failures to weak front plates flexing and wipping out the linings. IIRC the Pioneer brand converters sold at O'Reilly recently changed theirs to a billet front plate that is $500?

6L80 has not even been on my radar. I have planned for a manual valve body Ried case TH 400.
Failure is common?