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Discussion Starter · #1 ·
Ok i just realized i had a fresh rebuilt 350 engine sitting in a 2x 1978 3/4 ton chev. that was going to the scrap yard.
I have a 90 yj with the 2.5 and am finally putting 2 and 2 together and am not sure where to start or if it would be worth converting to fit in the yj.

first question, should I?
the goal is to run at least 37's and axles sometime.

Next what kind of fuel injection conversion should i get for it?

And then what kind of trans would i need? auto manual?
The goal is crawler mode with some street ability.
and i was planning on just mating with my np231j but would be open to better options.

Thanks!
 

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Why not just use everything from the chev?? Engine, trans, transfer, axles?
 

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Discussion Starter · #3 ·
its a 2x4 ifs so trans and tcase would not work or front axle
 

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Look at Novak or advanced adapters to see what options they have. I think you bolt just about any transmisson / transfer case to a small block chevy even if it is a 2wd. I believe you would just remove the tail section of the tranny to bolt up a transfer case.
 

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Discussion Starter · #6 ·
propane sounds cool. ill look into that. i know there are adapters and what not but i have no clue what tranny would be a good one, or how to identify, so if anyone has input on this that would be awesome
 

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Why not just use everything from the chev?? Engine, trans, transfer, axles?
Ah ha..... I see, well the trans and rear axle might be usable. Can always get something from Novak to hook it up to the t-case you have now. Then you just need a fron axle?
 

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Swapping a Chevy V8 into a Jeep is entirely worth it. You can do it on a budget or you can blow as much money as you want. It's not all that hard if you know your way around your tools.

Use the Novak Chevy engine mounts to put the engine in. It'll let you customize where it sits in the engine bay. You'll need to weld them in but the flexibility they give you makes life a ton easier. You will need to get a conversion radiator but you'll want a bigger radiator than came with the 4 banger anyway. They're not expensive.

If you like automatics, the 700R4 is hard to beat. You'll want to push your engine forward a bit to help make room for it in the YJ but that's not hard to do. The 700R4 bolts to the Chevy engine with no modification. A shorter alternative is the TH350. It doesn't have overdrive like The 700R4 but it's nice and compact.

If you like manuals, the SM465 is a good choice. It came behind Chevy engines so as long as you get the bellhousing with it, it's a bolt up with no modification. If you can find one, the NV4500 from behind a Chevy is also a good choice. It usually needs some minor fixes to stock flaws but a good rebuilder can do that for you.

For transfer case, a Chevy NP241 is a great option. It will bolt right up to any of those Chevy transmissions with no expensive adapters and it even drops on the drivers side (except for the first few model years). You'll probably need to put in a SYE to make the drive shaft fit but there's plenty of good options for that.

As far as axles, plan on replacing the factory axles. The D30 and D35 will never hold up to a V8 with 37's. A front Dana 44 built right can do it. A D60 or custom 9" with D60 knuckles would be better. In the rear, a built D44 would be adequate but a 9" or D60 would be better.

You'll want to gear the axles to match your transmission (with or without overdrive) and tires. But that's not hard to do, especially if you go with custom built axles.

As far as fuel injection, it's not hard to hook up factory throttle body ignition from a late 80's/early 90's Chevy V8. There's a ton of aftermarket options available as well. It all depends on your budget. You can go with inexpensive throttle body systems to full self tuning port injection. Propane is an option that some people have a lot of luck with. But consider that the Quadrajet carburetor on Chevy engines is probably one of the best factory carburetors for off roading out there. It's not perfect but it does really well for a carburetor. If you're on a budget, you can leave the Qjet on and do plenty of wheeling while you save up for fuel injection.
 

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Discussion Starter · #9 ·
Thanks Derf. That is what I was looking for. Ill have to see what trans is on my old truck. Like I mentioned the trans and motor have about 5000 miles on it before it was parked due to other issues. My brother still runs it around our property and says it is great. I used to pull my buddies 4runner to moab with it in highschool a few times a year. I loved that truck. But Its at my parents house in utah and I'm 4 hours away so it will probably be a while before I get to start this but I want to have everything good to go when I do it. Ill look at novaks mounts. My current tcase has the sye and was recently rebuilt so I was planning on running it. I have a buddy that has been running the same on his v8 xj with 38s and its doing good.
 

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Discussion Starter · #10 ·
ok im looking at a few things here. were there ever d60s in chevy trucks in the 70s? found a guy parting out a 3/4 ton claiming one is in there, also does anyone have any info on the turbo350 trans this one is in auto?
 

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Discussion Starter · #12 ·
My motor runs ok. Leaks like a siv though. But it probably won't be out untill january or later.
 

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ok im looking at a few things here. were there ever d60s in chevy trucks in the 70s? found a guy parting out a 3/4 ton claiming one is in there, also does anyone have any info on the turbo350 trans this one is in auto?
Front or rear D60? I'm not entirely up on 70's era chevies but I know they did run the front D44 until they swapped over to the 10 bolt. I'm not sure about the D60 in the 3/4 ton. Axles in the rear were typicially corporate axles. You'd typically find at least a 12 bolt if not a semi-float 14 bolt out back. I think the full float 14 bolt was only in the 1 tons.

Thing is, though, those axles are going to be seriously wide. If you're building your Jeep to run on the street keep in mind that the wheel mounting surface is like half a foot out on either side. Google something like "jeep on full width axles" to see how far out the wheels are when you do that conversion. Secondly, the front differential is going to be on the passenger side in a 70's Chevy. That won't work unless you go with a different transfer case. Third, the differential sits outboard more than a Jeep axle so you'll either have to move the springs outboard of the frame (there's kits to do that) or shorten the long side axle tube.

It's not impossible to get Chevy axles to work, there's just a bunch of things you have to consider when you do it.

One option that people do is to use axles from an 80's Grand Wagoneer. It's a Dana 44 front with either a heavy duty AMC20 (stronger than the one on the CJ) from 1980-1986 or a Dana 44 from late 1986 to 1991. They're the right width, driver side drop front, and the differential isn't sticking out in the middle of where the spring wants to go. They're 6 lug axles but if you're swapping tires you can pick up the rims at the same time and you're good to go.
 

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I like full widths in a YJ, they drive so much better. Mine is only about 4 inches wider overall than my dad's YJ, but I also run narrow tires.
I may have been exaggerating on how much wider they are but it's certainly noticeable. And in some states you can get in trouble if your tires aren't mostly covered by fender flares. Full width axles and big tires make that difficult. That's not good or bad, just one thing you'll have to look at when planning the build.
 

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Discussion Starter · #16 ·
The reason I ask about the 60 is a Guy is claiming one under his Chevrolet he is parting out with 411 gears for 250.00. If that is a deal I don't want to pass up on that.
 

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Discussion Starter · #17 ·
I am also putting on tube fenders front/rear and will have 7" or less to work with depending on what axle I use. So I'm not too concerned with that. But I have been looking for the waggy 44s
 

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Discussion Starter · #19 ·
Ibuildembig said:
Yeah it is, chevy ones bring about 700-900 depending on condition. Make sure it is what he says first. I dont think they ever put one in a 3/4 ton from the factory.
That is what I was thinking about not being stock. The truck seemed to be halfway built I believe but still have not talked to the person parting it out.
 
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