V8 in a TJ

Gadget

Caught the Bug
Toying with the idea of putting a v8 in my 99 TJ instead of another 4.0, I know it's been done many times. Just wondering which v8 would be the best/easiest choice? I'm just looking for a little more power and possibly somewhat better mileage than my tired 4.0, also anyone that has done this what was involved in making it work?
 

cmireles

Member
Toying with the idea of putting a v8 in my 99 TJ instead of another 4.0, I know it's been done many times. Just wondering which v8 would be the best/easiest choice? I'm just looking for a little more power and possibly somewhat better mileage than my tired 4.0, also anyone that has done this what was involved in making it work?

I've heard of someone putting a 5.3 LS in a TJ before. Better mpg and HP. Also, 505 performance has stroker kits or full turnkey engines available for the 4.0 but apparently there have been a bunch of issues with those.
 

Gadget

Caught the Bug
From what I have read about the stroker motors you have to run premium gas in them or they run crappy. I just don't want to pay more for gas.
Will the stock 5sp manual transmission and NP231 T-case hold up for daily driving and light weight wheeling with a v8?
 

mudmobeeler

Caught the Bug
From what I have read about the stroker motors you have to run premium gas in them or they run crappy. I just don't want to pay more for gas.
Will the stock 5sp manual transmission and NP231 T-case hold up for daily driving and light weight wheeling with a v8?

You could try to find a complete running vehicle for the swap. That way you would have the drivetrain, wiring, etc. I dont know what motor you are looking for but the 88-95 chevys can be found with throttle body fuel inj v8s, 5 speeds, and 241 cases which would be a little better than your 231 and still be a driver side drop. The 96-99/2000 body style chevys would be a better motor than the throttle body ones. The NV3550 5 speed is ok for a mild build, they were in the s-10 series and the light duty 1/2 tons and 3/4 tons. The nv4500 would be probably one of the best 5 speeds you could do if not the best. It can be found in the heavier 3/4 tons and the one tons.

Of course the LS style of motors would be better yet. Their cost is starting to come down also so they are comparable to the older motors. I know the 5 speed was offered behind the truck motors but not sure which ones. There was also a 6 speed, again Im not sure. Due to not selling as many of the standards they didnt produce that many per say. You can get adapters to do an NV4500 behind an LS style also. I dont think it was ever offered that way from the factory, but could be wrong.

If I were just wanting a v8 and maybe a mild build on it, I would find a 96-99/2000 body style chevy 4x4 one ton with the 350 and the nv4500 5 speed. Would give you the v8 power that you could build, would give you a stout 5 speed tranny, and a 241 case that will either be heavy duty or that could be made better. Think they offer kits to convert it to a 5 or 6 gear planetary gear from a 4 gear as well as a heavier/wider chain. Along with a slip yoke eliminator kit.
 

suicideking

New member
Most of the ones I've seen are Chevy's, though I've also seen it done with a Hemi out of a RAM. Loyalists will go with the Hemi.
 

sed8ed

New member
I did a 360 swap (5.9l) in my 97 and it was pretty straight forward. Picked up a wrecked grand cherokee of the same year with the engine in decent shape and the engine mounts will line up since that vehicle was offered with a 4.0 as well as a 318 (5.2l) and a 360 (5.9l).
The AX15 is a little weak to be behind the 318 and way too weak to be behind the 360 so try to find an older dakota to source a 3500 or 3550 out of (a 4500 would be nice as well but it adds significant weight, often has poor gear ratios and adapters will be needed for the transfer case). Some TJ's came with 3550's so if you have one, you are already ahead of the game.

I used the PCM out of the WJ and has it reprogrammed but the company that did it is now out of business. After I scrapped what was left of the WJ and the TJ engine, I was in for just under $800 for the swap however my fuel economy went from poor to non-existent so I made up any cost savings there.

Good luck
 

notnalc68

That dude from Mississippi
You could try to find a complete running vehicle for the swap. That way you would have the drivetrain, wiring, etc. I dont know what motor you are looking for but the 88-95 chevys can be found with throttle body fuel inj v8s, 5 speeds, and 241 cases which would be a little better than your 231 and still be a driver side drop. The 96-99/2000 body style chevys would be a better motor than the throttle body ones. The NV3550 5 speed is ok for a mild build, they were in the s-10 series and the light duty 1/2 tons and 3/4 tons. The nv4500 would be probably one of the best 5 speeds you could do if not the best. It can be found in the heavier 3/4 tons and the one tons.

Of course the LS style of motors would be better yet. Their cost is starting to come down also so they are comparable to the older motors. I know the 5 speed was offered behind the truck motors but not sure which ones. There was also a 6 speed, again Im not sure. Due to not selling as many of the standards they didnt produce that many per say. You can get adapters to do an NV4500 behind an LS style also. I dont think it was ever offered that way from the factory, but could be wrong.

If I were just wanting a v8 and maybe a mild build on it, I would find a 96-99/2000 body style chevy 4x4 one ton with the 350 and the nv4500 5 speed. Would give you the v8 power that you could build, would give you a stout 5 speed tranny, and a 241 case that will either be heavy duty or that could be made better. Think they offer kits to convert it to a 5 or 6 gear planetary gear from a 4 gear as well as a heavier/wider chain. Along with a slip yoke eliminator kit.

^^^^ If I had a TJ & was looking to get rid of the straight 6, I'd go with the '96-2000 Chevy 5.7L. Plenty of power, good reliability, and should be easier on gas, than the 4.0, even though it has note displacement.
 

ob_tj

New member
I am in the same situation as you. Have 98k miles on my 04 TJ and soon it will be time to do a V8 swap. I have heard the Chrysler 289 is a good little motor to put in a TJ.
 

NavyJeeper

New member
I'm looking into the same thing dropping a v8 in mine as well. Got everything i need and some great info from novak conversions, you should check em out! give some great info
 

piginajeep

The Original Smartass
I wouldn't waste the money. Just put a stroker kit in a the straight 6, it's super fast and reliable
 

mudmobeeler

Caught the Bug
I wouldn't waste the money. Just put a stroker kit in a the straight 6, it's super fast and reliable

Thats another option as well, and from what Ive seen and heard a great option.

While I could argue the cost of this vs a v8 swap, I would not throw this option out the window. It would all depend on what I was gonna do with the vehicle.
 

tdans

New member
I know a few people who had Novak Adapters put in a v8. Its expensive and $$ but they run amazing and get way better gas mileage. Someday I hope to put one in mine. Check out their website it will give you information on motors transmissions and transfer cases. or give them a call they are super nice and will let you know anything you need to know.
 
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