Gen III Hemi Swap into TJ Reference Guide & Swap Info

[Wildman]

@Daubie3 noticed & commented in my build thread that I'd installed the bracket upside down. So I flipped the bracket around and using the predrilled holes mounted the pedal.

But setup like this the pedal was rubbing on the floorboard near full throttle.

So I pulled the bracket back off and drilled new holes a little higher & just a little more away from the transmission tunnel.

This for me works a LOT better.

 

[Daubie3]

@Daubie3 noticed & commented in my build thread that I'd installed the bracket upside down. So I flipped the bracket around and using the predrilled holes mounted the pedal.

View attachment 554044

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But setup like this the pedal was rubbing on the floorboard near full throttle.

View attachment 554047

So I pulled the bracket back off and drilled new holes a little higher & just a little more away from the transmission tunnel.

View attachment 554048

This for me works a LOT better.

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Does it sit more comfortable for you now?
It looks a lot better in the pictures..

 

[Wildman]

Does it sit more comfortable for you now?
It looks a lot better in the pictures..

It's better than it was when the bracket was turned upside down.

 

[Daubie3]

It's better than it was when the bracket was turned upside down.

That's great!
I wasn't 100% sure but it looked upside down in your pictures.. I thought it's odd that it would actually be able to mount it either way..

I'll bet we're the only 2 ever that had it wrong the first time...

 

[Wildman]

That's great!
I wasn't 100% sure but it looked upside down in your pictures.. I thought it's odd that it would actually be able to mount it either way..

I'll bet we're the only 2 ever that had it wrong the first time...

I'd looked everywhere trying to find something that showed which way it was supposed to mount and couldn't find it. So then I was trying to both ways and still couldn't figure it out. Then me trying to fit my foot in the area with it not bending at the ankle just made it worse.

 

[Steelyace]

I realize this is a gen 3 hemi swap thread but has anyone utilized a gen 4 in this group? I am really close to ordering a crate gen 4 to put in front of the 8HP70 I already have. I have talked to Chris at Hotwire, and I am fully aware I will have to run after market gauges, but it seems that it shouldn't make it more or less difficult or viable than a gen 3. The benefits are it comes as a non-MDS engine and of course it is an eagle engine.

 

[Wildman]

I realize this is a gen 3 hemi swap thread but has anyone utilized a gen 4 in this group? I am really close to ordering a crate gen 4 to put in front of the 8HP70 I already have. I have talked to Chris at Hotwire, and I am fully aware I will have to run after market gauges, but it seems that it shouldn't make it more or less difficult or viable than a gen 3. The benefits are it comes as a non-MDS engine and of course it is an eagle engine.

Try talking with Todd at JeepSpeed Shop. He might be helpful with some information.

 

[pc1p]

I realize this is a gen 3 hemi swap thread but has anyone utilized a gen 4 in this group? I am really close to ordering a crate gen 4 to put in front of the 8HP70 I already have. I have talked to Chris at Hotwire, and I am fully aware I will have to run after market gauges, but it seems that it shouldn't make it more or less difficult or viable than a gen 3. The benefits are it comes as a non-MDS engine and of course it is an eagle engine.

Assuming you’re referring to Gen IV as a later year (2009+) VCT (aka VVT) engine?

If so, it’s very popular. I’m swapping a 2010 Gen IV 5.7 and 8HP70 into my JKU this spring (just got a block and will be going through it and adding an HRT cam, non-MDS lifters, etc).

Todd at JSS is the man for JK swap info, but I’m sure there’s a lot he can help you with in your TJ swap too. I’m sure the Hotwire crew is a good bunch of resources as well. Much will be similar to the Gen III swap, though perhaps more like an LS swap since you won’t get much to link up with your OEM gauges. I think Autometer still makes an OEM style gauge cluster. With some basic wiring, you should be able to integrate a CEL and other lights that will make it similar to factory operation.

 

[pc1p]

In case anyone wants to follow my Hemi swap currently in the prep-stage…

https://wranglerjkforum.net/threads/2008-jku-argenta-build-thread.32367/

I have my axles to finish building at the moment and will then work on going through the 5.7L I recently picked up. Currently sourcing a 8HP70 as well, plus many of the OEM BOM #’s that I’ll need to get this done this spring…

 

[Wildman]

In case anyone wants to follow my Hemi swap currently in the prep-stage…

https://wranglerjkforum.net/threads/2008-jku-argenta-build-thread.32367/

I have my axles to finish building at the moment and will then work on going through the 5.7L I recently picked up. Currently sourcing a 8HP70 as well, plus many of the OEM BOM #’s that I’ll need to get this done this spring…

I've read that the 8HP70 is a game changer and have been keeping my eye out for one local for a good deal. But I really just want to get the Jeep on the trails for a while first before I even think about doing anymore serious wrenching on it.

Good luck with the Hemi swap into your JKU...

 

[Hammer_c]

I realize this is a gen 3 hemi swap thread but has anyone utilized a gen 4 in this group? I am really close to ordering a crate gen 4 to put in front of the 8HP70 I already have. I have talked to Chris at Hotwire, and I am fully aware I will have to run after market gauges, but it seems that it shouldn't make it more or less difficult or viable than a gen 3. The benefits are it comes as a non-MDS engine and of course it is an eagle engine.

Biggest hurdle I see is making an integrated harness and getting the modules tuned out to work with a TJ. This is a very popular swap in the JK world and works well, but not sure if the demand is there for the TJ and if anybody has a tune for it. Todd flashed my 6.1 8HP70 last year and has a wealth of knowledge but at the time was not supporting gen 4s in TJs. Hopefully now there’s support for it since a gen 4 would be a sweet option!

Gas Monkey Garage put a hellcat in a 60s Dart so it’s possible as a stand alone, just not sure how much $$$ or time.

 

[Hemic]

I realize this is a gen 3 hemi swap thread but has anyone utilized a gen 4 in this group? I am really close to ordering a crate gen 4 to put in front of the 8HP70 I already have. I have talked to Chris at Hotwire, and I am fully aware I will have to run after market gauges, but it seems that it shouldn't make it more or less difficult or viable than a gen 3. The benefits are it comes as a non-MDS engine and of course it is an eagle engine.

Chris can make you the harness. He can also integrate the H8P70 harness and PCS into it.
If you're concerned about emissions, run the Dakota digital cluster + the new engine, and Hotwire harness.
Your rear defrost I think needs to be rewired as it runs off of the factory TJ cluster circuit.

I'm running 6.1L + 8HP but as a manual engine ECU (Ram 2005) + stand alone transmission module (Sound German), but if emission legality isn't an issue you can run a factory 392 or 5.7 ECU that also communicates with the 8HP. Chris from Hotwire offers that option.

 

[Steelyace]

Chris can make you the harness. He can also integrate the H8P70 harness and PCS into it.
If you're concerned about emissions, run the Dakota digital cluster + the new engine, and Hotwire harness.
Your rear defrost I think needs to be rewired as it runs off of the factory TJ cluster circuit.

I'm running 6.1L + 8HP but as a manual engine ECU (Ram 2005) + stand alone transmission module (Sound German), but if emission legality isn't an issue you can run a factory 392 or 5.7 ECU that also communicates with the 8HP. Chris from Hotwire offers that option.

Emission will not be a problem for this jeep, so that helps. After talking to Chris I am looking at running a 2015 Ram ECU which will help with this engine and transmission combo.

 

[pc1p]

I've read that the 8HP70 is a game changer and have been keeping my eye out for one local for a good deal. But I really just want to get the Jeep on the trails for a while first before I even think about doing anymore serious wrenching on it.

Good luck with the Hemi swap into your JKU...

It’s a game changer for many reasons, especially if you intend to add some HP and big tires… it’s a really easy swap, you don’t even need a shift cable!

 

[NashvilleTJ]

The Gen IV works well in the JK because the frame rails are a bit wider. The main issue with putting a Gen IV in the TJ is the location of the accessories - they interfere with the frame in the standard configuration. It can be done, and has, but it requires a good bit of modification to the frame to clear the accessories.

That said - the Gen III is ugly, especially with the alternator and A/C compressor sitting up on top front and center. The Gen IV is much cleaner.

 

[Wildman]

It’s a game changer for many reasons, especially if you intend to add some HP and big tires… it’s a really easy swap, you don’t even need a shift cable!

What is the length difference between a 545RFE & a 8HP70? Seems like it might be a OK swap if length isn't an issue but I'm not sure what I'd need to add to run it in my TJ. I'd guess a stand-a-lone TCM? Not sure what else but might have to talk to Todd & Chris some more about doing it.

 

[Hammer_c]

What is the length difference between a 545RFE & a 8HP70? Seems like it might be a OK swap if length isn't an issue but I'm not sure what I'd need to add to run it in my TJ. I'd guess a stand-a-lone TCM? Not sure what else but might have to talk to Todd & Chris some more about doing it.

Not sure the length differences but the TCM is inside the trans and the stand alone harness has the controller for the required CAN, tach, and brake inputs. You’ll need at least the following.
- 4WD 8HP70
-Challenger Shift
-Gas pedal
- Wagoner or jl cooling lines
- Stand alone wiring harness and control from sound German. Hotwire and JSS use this.

 

[Wildman]

Not sure the length differences but the TCM is inside the trans and the stand alone harness has the controller for the required CAN, tach, and brake inputs. You’ll need at least the following.
- 4WD 8HP70
-Challenger Shift
-Gas pedal
- Wagoner or LJ cooling lines
- Stand alone wiring harness and control from sound German. Hotwire and JSS use this.

OK great & thanks.... So the ones I'm seeing for $500 when it's just the transmission really aren't going to help me? I need to talk with a junk yard and get a quote for all the parts.

I've thought about using this shifter instead of the Challenger shifter since I've got the GR center console.

I figure I could mount this under the GR console easier than I could a Challenger shifter.

 

[Hammer_c]

OK great & thanks.... So the ones I'm seeing for $500 when it's just the transmission really aren't going to help me? I need to talk with a junk yard and get a quote for all the parts.

I've thought about using this shifter instead of the Challenger shifter since I've got the GR center console.

View attachment 569313

I figure I could mount this under the GR console easier than I could a Challenger shifter.

Nice shifter! Not sure if that would work or not since you’ll need to flash the TCM to read the challenger shifter on a 4WD trans. Todd at JSS could probably answer that.

 

[Wildman]

Nice shifter! Not sure if that would work or not since you’ll need to flash the TCM to read the challenger shifter on a 4WD trans. Todd at JSS could probably answer that.

I really shouldn't even be thinking about trying to install the 8HP70 into my Jeep since I don't even have it driving yet. It runs & yes I've driven it but I've still got some small things to take care of before I'll call it good.

And then the idea of dropping the tranny & t-case to swap in a new transmission is really crazy... But I do like the idea of the 8 speed.