Swap dilemma

[70barracuda]

So I cannot take my 2.5 in the cherokee anymore. It is so abysmally slow and here in NJ is honestly dangerous.  So ill be swapping in a v8.  This one's going to be super basic, nothing like my comanche. Question is what to put in it. My brain says LS for obvious reasons but my heart says a good ol 350. Transmission will be a ax15 so itll work with either. This thing is super clean so I don't want to hack or cut up really anything. And I just feel like a 350 fits this jeep better than a LS. Opinions? If it do go 350 itll be the last years of it, the roller cam vortec. LS will be a 4.8 or 5.3. 

[89 MJ]

Would you keep the Vortec FI on the SBC? 

 

Personally, I prefer an SBC to an LS because it has always felt to me that an SBC's torque peak is at a lower RPM than an LS's. That said, a Chevy 350 is old technology at this point, I don't think they've been put in a new GM vehicle since 2002, nor is it as efficient as an LS. 

 

I would guess that the work involved for a small block versus an LS would be about the same.

The LS would more than likely cost more than the SBC, but I think the higher resale value more than makes up for that difference. 

 

I think an LS is the way to go on this one. 

[70barracuda]

2 minutes ago, 89 MJ said:

Would you keep the Vortec FI on the SBC? 

 

Personally, I prefer an SBC to an LS because it has always felt to me that an SBC's torque peak is at a lower RPM than an LS's. That said, a Chevy 350 is old technology at this point, I don't think they've been put in a new GM vehicle since 2002, nor is it as efficient as an LS. 

 

I would guess that the work involved for a small block versus an LS would be about the same.

The LS would more than likely cost more than the SBC, but I think the higher resale value more than makes up for that difference. 

 

I think an LS is the way to go on this one. 

I would probably run holley sniper on the 350. 

 

But yeah,  I know the LS makes the most sense. Its just I've already done it and want something a little different. As different as I can be with a 350 haha. Either swap is going to be pretty easy. 

[Eagle_SX4]

My first choice for a V8 swap would be a L33.

 

Second choice for something different would be a LV1. It is the GM LT based 4.3 v6. 2018+ full size van motor. Not very much after market support and would be as much work as an LS swap but with more room in the engine bay.

[Eagle_SX4]

Check out this article on the LV1/LV3.

https://www.holley.com/blog/post/can_a_modern_v6_swap_work_we_check_out_holley_s_lv1_v6-swapped_pontiac_development_test_vehicle/

 

[70barracuda]

24 minutes ago, Eagle_SX4 said:

Check out this article on the LV1/LV3.

https://www.holley.com/blog/post/can_a_modern_v6_swap_work_we_check_out_holley_s_lv1_v6-swapped_pontiac_development_test_vehicle/

 

Now that would actually be a perfect swap. I have to research that alot more. 

[derf]

If I was going to swap a classic small block Chevy, I'd probably do a 383.  It can be done with the Vortec setup pretty easily if you want.

 

But if I had time and money to burn, I'd look at doing a small block Ford.  A 302/5.0 would tuck in that engine bay nicely.  You would need to do more fabrication but you could start with the frame side mounts for a Chevy and make engine side brackets to fit.  Everyone does Chevy swaps.  A Ford would be unique.

[89 MJ]

47 minutes ago, Eagle_SX4 said:

Check out this article on the LV1/LV3.

https://www.holley.com/blog/post/can_a_modern_v6_swap_work_we_check_out_holley_s_lv1_v6-swapped_pontiac_development_test_vehicle/

 

That would be a perfect engine! As long as it isn't too difficult compared to an LS, that would definitely be the way to go.

 

12 minutes ago, derf said:

But if I had time and money to burn, I'd look at doing a small block Ford.  A 302/5.0 would tuck in that engine bay nicely.  You would need to do more fabrication but you could start with the frame side mounts for a Chevy and make engine side brackets to fit.  Everyone does Chevy swaps.  A Ford would be unique.

This would be neat too, especially if it isn't a daily driver. It's always been my (admittedly biased) understanding that GM swaps are typically a lot cheaper and have better parts availability, which is why I'm assuming you added the time and money to burn part.

[70barracuda]

I had thought about doing the original 4.3 swap as my cherokee is an 86 and has the different engine bay dimensions. But so much research led to me to its v6 power with v8 economy so really no point. My goal with thing is a super reliable daily, A/C, easy driving and great mileage. 

 

The newer 4.3 seems like it would be a great swap and the aftermarket is slightly there. Just have to make sure itll work with my ax15 or even a nv3500. 

[derf]

2 minutes ago, 89 MJ said:

That would be a perfect engine! As long as it isn't too difficult compared to an LS, that would definitely be the way to go.

 

This would be neat too, especially if it isn't a daily driver. It's always been my (admittedly biased) understanding that GM swaps are typically a lot cheaper and have better parts availability, which is why I'm assuming you added the time and money to burn part.

Yeah.  It's a self feeding cycle.  Everyone does Chevy swaps because everyone does Chevy swaps.  Parts for Chevy swaps are plentiful.

 

Ford and Mopar are arguably similar in capability but the lack of bolt in swap kits make them rare.  So nobody makes the kits.  So nobody buys them.

 

If you can fabricate the mounts, you still have all of the nitpicky details to sort out on your own.  The Chevy swap kits cost a bit but they bolt right in and save you a bunch of time and (when you add it all up) money.

[Eagle_SX4]

24 minutes ago, 70barracuda said:

I had thought about doing the original 4.3 swap as my cherokee is an 86 and has the different engine bay dimensions. But so much research led to me to its v6 power with v8 economy so really no point. My goal with thing is a super reliable daily, A/C, easy driving and great mileage. 

 

The newer 4.3 seems like it would be a great swap and the aftermarket is slightly there. Just have to make sure itll work with my ax15 or even a nv3500. 

The bellhousing pattern is largely the same as the LS except for the top center bolt was moved to accommodate the fuel pump. It looks like the quickdraw ax15 to LS bellhousing is drilled to accommodate the top bolt shift of the LT engines. It is not listed on their website as being compatible but the bolt hole appears to be machined into the bellhousing.

 

https://quickdrawbrand.com/general-motors/bell-housing-jeep-ax15-nv3550-5-speed-to-gm-ls-v8/?srsltid=AU7gw4UiJ2hE8w2xo7TLB5KQiHp-xXuEpBZfoYDqMWu1aSQ17_8gIJjO

 

 

[ThatJeepGuy]

My not soo old school knowledge base and thus prolly limited on the new school front as well for motor head stuff...

 

If you wanted a carb setup - 350 if you wanted a fuel injected setup - LS.

 

I'll be upfront as I can hahaha...

 

I have a few ls swapped jeeps some ive done/doing and one ive bought finished. Don't mind the work going into them... fuel injected and parts availability - the price and availability for finding replacement motors - it appeals to me.

 

For me and my lack of experience with diverse engine packages (ima jeep 4.0 and LS kinda fella). I think if I had an engine combo that I would play with a carb on to learn and experience it - i would go 350 - again because of the price and availability for finding replacements.

[75sv1]

Someone did a Ford 5.0 Comanche a while back on this board. It was Fly Yellow. The V6 with an aluminum block would be awesome. Less weight. Plenty of power. 

[88mjsally]

I have done both a vortec V8 and am finishing an LS swap now. I drove my Vortec v8 all through college and it was a great driver with sniper EFI and I find it simpler than the LS. If I ever V8 swap another one that’s the route I’d probably go again

[ghetdjc320]

I’d go LS. Modern and efficient. I’ve done many gen 1 and 2 GM engines too and like the platform. But I’m done with carburetors, distributors and any version of throttle body injection. Plus I do look at the resale value of what I build. 350 swaps tend to be bottom dollar in the world of v8 swaps. It’s nice to have a matching numbers engine for certain clean restos. But when you’re already engine swapping, go for the most well supported platform imo

[dasbulliwagen]

Just something to think about. I'm pretty sure that the 4.0 belhousing bolt pattern is the same as the AMC V8s. 304, 360, 401?!? And it's been a long time, but I think I remember someone in the build section doing a Chrysler 318/360 swap trying to use mostly all factory made parts. Just a couple of other options for you. I looked into the diesel 4BT swap a long time ago, but the costs got a little ridiculous fairly quickly. The little 2.5 in mine is pretty much the only thing I've never had to touch on my truck, and as long as it keeps going, I'm not going to worry about it. Yeah it's slow, but I've come to terms with it. 

 

[derf]

The 304/360/401 share the bellhousing bolt pattern but they're bigger than the small blocks from Ford, GM, and Mopar.  They are hard to fit.  As is the 4BT.

[DirtyComanche]

On 9/17/2026 at 6:54 AM, Eagle_SX4 said:

Check out this article on the LV1/LV3.

https://www.holley.com/blog/post/can_a_modern_v6_swap_work_we_check_out_holley_s_lv1_v6-swapped_pontiac_development_test_vehicle/

 

That's cool.  Real good compromise for having it fit, a good upgrade for power, and still fuel efficient.

[70barracuda]

Been researching the newer 4.3 and there's just not a ton of info out about it. Apparently they came manual from the factory in Mexico but parts are next to impossible to find. And no one really makes an easy swap harness for it. 

 

I'm trying to make this a fairly easy and quick swap. The comanche is really my "let's try this" vehicle. I want the cherokee to be super basic and as easy as a swap as possible. 

 

I think I've come to terms with an LS, has to be an all aluminum though. unless a really good deal on a small block happens. Trying to pick up an nv3500 as I can save money on no adapter needed for the ax15.