Official 350 swap

[YJCrawler19]

so... it is now official. Over the winter, the YJ will be getting a 350 out of a 1989 chevy 1500 (the donor truck has been found). I havent looked at the tranny yet, but I'm guessing it is a th350 or 700r4. Not the th400 I wanted, but I think I'll take it anyway. Either is still a good tranny for a Jeep. The question is; Has anyone here undertaken the above common swap, and how long did it take YOU? Im not looking for web search info... I have looked into that. Im looking more for the info from people I know. If you kept your np231, are you happy with the descision or do you wish you did something else? If you did the swap, do you have any recomendations based on experience, or on things you wish you did differently? Any input is appreciated and will help me plan this swap a little better.
Thanks!

[grundlepunch]

why are you doing this? whats wrong with the motor in your jeep? the 350 is throtle body right? if so i would just put a 4.0L jeep motor in it or do a sick swap like a 5.3L

a lot of my friends have done v8 swaps, most went fuel injected. all of them are a headache. on a side note my friend is selling a amc 360/th400 out of a j2000 with 55k miles on it

[YJCrawler19]

Right now the yj has a 4.2 and is a bucket of headaches with absolutely no power. The donor truck is $free.99, and everything is working nicely in it. I want to go with a v8 and this motor is unbelievably easy to get parts for. I would also like to get away from the carb and its off camber issues. I thought about a 360, 351w, 305 (almost went for this one), buick v6, and a couple others, but this one kinda fell into my lap. There is just so much aftermarket support for the 350's its stupid. I figure its worth a try.

[Danksters]

If you saw my yota buildup thread, you would know that I am doing a 350/700R4/NP241 combo. The small block is carbed with a quadrajet.

Suggestions:

Bolt up the entire drivetrain when you do your test fitting.

Look out for radiator and fan clearance.

Distributor clearance.

What are you doing for exhaust: manifolds or headers? clearance

Motor mounts: DO NOT burn them in(if you are doing weld in) until you have checked everything 17,000 times and then check it some more. Just heavy tack them until you are absolutely positive you have it where it needs to go.

Check driveshaft clearance with tranny pan, especially if you are not running full width axles, may have to use a smaller OD thicker wall front d-shaft.

What shape is the oil pan? Will it interfere with your axle/link brackets/steering?

don't forget about the millions little things that add up to lots of money, like fluids, nuts/bolts, gaskets, tune-up parts, .......

[yj350]

Tim when are we doing it ? I will give you a list of the stuff we used to do mine. As long as you have every thing out it can be put in in a long weekend. you can probably figure about $2000-$2500 to do it right and do it once.

[OWEN]

I put a TBI 4.3 in my flattie kinda similar. Heres my input.

Driveline length.
The 700R4 is pretty long. If it is 2wd I think you will find trouble adapting it to a np231, which is also a long transfer case. I originally was going to run a 700r4/231C with a SYE in my flattie (which by the way has a longer wheelbase than a stock YJ), but I found the length was way too long to have a realistic rear driveshaft. I think the overall measurement from the bellhousing mating surface to the output yoke for the 700r4/231 was about 45", and that is with an SYE. I lost over 10 inches of driveline length by switching to a manual trans. Side note: My friend runs a 350 with an sm465 novak adapted to a D300 and has a 30+ inch rear driveshaft.

If you are going to run a 231, look into running a 700r4 from a 4.3 powered s10 4wd. This 700r4 is equal to those behind v8s from what I have read, and are vactory adapted to a 27 spline (input) 231C which uses a 6 pinion planetary and wider chain than the jeep versions, meanwhile the SYE kits are compatible.

Here is a pic of my 4 speed (np435) next to a 700r4


Cooling.
Don't skimp especially if you are going to wheel it. A lot of guys are running factory electric fans off of 90-95 3.8 Ford Taurus with success. Theres a lot of options at the junkyard. Dont forget an adequate sized radiator either. I used a 4 core Toyota FJ 40 radiator (same inlet/outlet config as a chevy small block) with a Mercedes electric fan


Placement.
Make it as high as you can without the air cleaner hitting the hood, if you are going to wheel it. You will have an easier time with the tub off, just note your hood height and firewall location, before you take it off. Make the engine as far forward as you can to maximize your rear driveline length, just be sure to leave room for your cooling.

Axles.
Will the stock ones hold up?


Thats what I can think of right now. Novak adapters has a great knowledge base for jeep engine swaps. You can check them out at www.novak-adapt.com

[yj350]

X2 on the novak adapters that is what I used and their customer service is second to none.