TBI 350 in a YJ - Is it worth the trouble?

[idahoyj]

I currently have an '89 YJ with a FI 2.5 4cyl, AX-5 with Tera Low NP231 case. It runs OK.... But it is just a 4cyl....
I have a line on a good running TBI 350/NP465 and whatever T-case it's bolted to, from an '87 3/4 ton. I can have all of the wiring/accessories/etc that I may need for around $350 if I pull it. The mileage is unknown, but it is a running and driving rig that got T-Boned and is headed for the crusher. My rig is currently on 1-tons with 4.10s, Ford 60 front, Sterling 10.5 rear, and I'm swapping 42" iroks onto it this Friday. The rig had 37s on it for a couple of runs, but I went crazy and bought 42s (off of RME!) I am sure with the 4:1 Tcase it will wheel OK in the rocks, but i like to wheel snow and the 4cyl wont have enough power to pull the 42s aired down in 4WD HI. I think the 4:1 will be too low and I'm affraid of burning it up by driving in 3rd/4th gear while in low range.
The cost of the conversion doesn't scare me too bad, because I will do nearly all of the work myself. I will hire out the drivelines and exhaust. Some of the cost will also be offset by selling the TeraLow case.

So, my question is-

Is a TBI 350 worth the trouble to swap, or should I just re-gear (5.38s) and let the deal pass on the 350? (I cant afford both this year).

I am leaning toward the 350 right now, but want advise from folks that may have done this swap. I think the 350 will still be underpowered with my huge tires and 4.10 gears in the snow, but if I had a standard Tcase with stock 2.72ish gear ratio, it would probably be pretty OK in the snow. With stock Tcase gears, I would be less worried about burning up the Tcase with higher speeds. Also, with the roughly 7:1 granny first gear in the 465 transmission, I think it would be pretty alright in the rocks too.
If I keep the 465 transmission, I would either need to find a passenger drop 241 Tcase and buy an SYE kit, or change to a passenger side drop front axle. I know where one is, and it is fairly cheap.
Or, I could easily bolt a Ford NP435 transmission in place and run a Ford, drivers drop Tcase.

Thoughts????
I just can't make up my mind, and somehow I think that my "faceless internet buddies" can steer me in the right direction.


(Sorry for rambling all of my thoughts out at once)
:chris:

 

[Tacoma]

My opinion is yes, yes it is. Throw an RV cam in it. 1st gear is 6.55:1 on that SM(not NP)465, and yeah, you should regear anyway. The NP241 is a good 2.72:1 case that may be already installed, if not they are readily available and easy to swap.

Axle shouldn't be an issue. For instance, I have either drop case available, and have a passenger drop 60, so a trade could easily be arranged. Etc. Proceed!

Put another way: the 350 is an engine you can "grow" your other mods into without running out of engine for a while.

 

[mbryson]

I'm running 4.56 axles, HIGH mileage TBI 350/700 and a Dana 300 (I've had stock gears and 4:1). I'd do the TBI 350. It's not the most awesome thing in the world, but the price is right and they are at worst, decent. If you're starting a fresh build, I'd lean towards a 5.3l or 6.0l. For low buck effectiveness, its tough to beat a TBI 350.

You'll ultimately want to change diff gears but you'll be Ok for a while with the granny gear.

 

[Bart]

Absolutely do the SBC.

 

[rondo]

I have not done this swap before but I think I know where you're coming from. My 4banger YJ on 37s in the snow even with my 5.38 gears was painful, underpowered and things got hot hot. probably the poor suffering clutch. on 42s I think you'll hate it
if I had your skills to do this V8 swap myself i'd do it in a heartbeat. now i'm running 38s and it can still rock crawl the technical stuff but 4:1 is now often inadequate. I've found the klune has to be engaged with the right gear as well on some of the hardest lines. and it still has no power to climb hard waterfalls. I would think 42s would be a suckfest.
I know a V8 is in my future according to the tea leaves but maybe a buggy. I spent my extra cash last 2 yrs on my WW2 jeep resto and I hate to "fix" an unbroken jeep at least for now.
good luck and show us the build when you get it going pls!

 

[mbryson]

.....If I keep the 465 transmission, I would either need to find a passenger drop 241 Tcase and buy an SYE kit, or change to a passenger side drop front axle. I know where one is, and it is fairly cheap.
Or, I could easily bolt a Ford NP435 transmission in place and run a Ford, drivers drop Tcase.

Thoughts????
I just can't make up my mind, and somehow I think that my "faceless internet buddies" can steer me in the right direction.


(Sorry for rambling all of my thoughts out at once)
:chris:

Re: the SYE kit: Snag a Dodge pass-drop 241 ('91-93 ?) and put your Chev input shaft into that. That might cost you $100-150. If you wanted to stick with the drivers drop axle, I wonder if the '94-newer ram has fixed or slip yoke 241 (really don't know on the "Ram" truck)

 

[idahoyj]

It looks like the overwhelming consensus is, GO FOR IT!
This is kind of the "belly buton" of Jeep swaps, so its widely documented and the aftermarket is very supportive.
My last "build" was based around a 5.3 and that is really what I would like to have, but it is just soooo much more expensive. I scrapped that build though.
I am planning to start a build thread soon. I have had the rig for several months and done quite a few mods/repairs so far. But, I cant find the cable to get pictures off of my camera.

Thanks for the input, and I will be looking here for more help when I start the swap later this summer or early fall.
Josh

 

[Spidey]

It's a walk in the park, but will cost you a lot more than you think. Is it worth it? yeah.

 

[jinxspot]

I've done the 5.7L swap once and many 4.3L TBI's and its super simple compared to other more extensive motor swap installs... I just recently picked up a rig with this 5.7L and am planning some cheap performance upgrades as listed:

I recommend the injector pod spacer and adjustable fuel pressure regulator from CFM tech. That not only will give you power, but about 2 MPG better. http://www.cfm-tech.com/index.htm
CFM-Tech Injector Spacer for GM TBI
CFM-Tech Fuel Psi Guage Adapter For GM TBI
CFM-Tech Adjustabe Fuel PSI Regulator for GM TBI
0-15 Fuel Psi Gauge
Hypertech Power Charger for Full Size Truck GM TBI
5.7 GM TBI balanced Injectors - Pair

Some other options with 5.7 TBI
Edelbrock 3704 intake manifold
Longtube headers and install an h-pipe in your dual exhaust, if you don't already have one
MSD ignition coil -- Gap your spark plugs to .060" with the MSD coil.
Hypertech Powercharger
Summit K1102 cam
Torque converter from a 4.3L S-10

When you're all done, GET A PCM TUNE! This is the most important part. Look around for Westers, PCM4Less, Wait4Me, etc. Do not get a Jet, or Hypertech chip, they will do nothing for you.

All this won't cost you all that much money, especially if you're on a tight budget. You'd be looking at about 50hp over stock, and a wider powerband.

 

[Gravy]

Yes. I love my V8 YJ

 

[larrybenny]

Once you go to V-8 power, you will never want to go back. With my 5.3 conversion I don't have to go to 4 lo near as often, have power in the sand, and average 20 mpg as a daily driver. This is with 4:56 gearing, 35 in tires, and a 4L60E trans combo.