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fatwreck 09-02-2009 01:22 PM

'88 YJ 5.3L Vortec Build Thread
About a month ago I bought this '88 YJ from someone on here with no engine/tranny. My intentions are for this to be mainly street driven with the occasional trip to the trail (2-3 time per year).

This is what it looked like when I bought it.

I weighed my options of inline six and some other possibilities, while working on a fairly tight budget...and this is what I came up with...

1 week later I had this 5.3L Vortec/4L60E tranny combo:

From there I had to figure out how to get the tcase mounted to the transmission without using one of those $550+ adapters.

The YJ did come with an NP231J transfer case out a '94 YJ. I tore that down to get to the input shaft. The Jeep setup is 31 spline. The 4L60E is 27 spline.

I ordered a 27 spline setup off of ebay. If you are going to do this, make sure you get the right input shaft an planetary gears to match your case. I think they changed in '94. The guy I ordered my stuff from had me send him some measurements before he sent me what I needed.

The tcase does bolt up to the 4L60E tranny, but it is clocked downwards at about 45 degrees. While that works great for driveshafts, it doesn't work so well for wheeling. I ordered this $60 clocking ring on ebay to get it straightened out.

fatwreck 09-02-2009 01:26 PM

The engine/tranny require a vehicle speed sensor to be used. From the factory it comes with 3 of them mounted in the transfer case. I ended up buying this one from AA. It's a $240 setup, but with this and the clocking rings above, it still ended up being cheaper than buying the entire adapter kit.

Once that was done, I could move on to bolting the tcase to the tranny. With those clocking rings, you usually end up only being able to use 5 of the 6 mounting studs. I thought I would just run it like that, because engineers usually use safety factors, right? :D However, once I got my Novak tcase shifter and realize it needed the one stud that I was going to be missing, I decided to slot the hole in the adapter to make it work with all 6 studs. it's time to get the engine/tranny mounted in the YJ.

Here it is going into the engine bay for the first time:

We mocked up the mounts using part of the Suburban mounts that came with the engine. They actually worked out pretty well. They are a little bulky, but it gave me a lot of surface area to weld to.

Here's dad torching out the passenger side mount:

fatwreck 09-02-2009 01:27 PM

Here's how the mount turned out on the passenger side:

And the driver side one is hard to see, but it's in there too:

We had to modify the belly pan to get the tranny mount to line up, but that wasn't too bad. Sorry, no pictures.

Here's how the engine sits now:

Firewall clearance:

Steering shaft clearance:

Front axle clearance:

And finally, belly clearance:

Lokar tranny shifter installed:

And the novak tcase shifter installed:

fatwreck 09-02-2009 01:28 PM

Here's how the tcase clocking turned out. I'm really happy with that.

And a shot of where the front driveshaft will go....plenty of room:

Now I'm moving on to the fuel system. I pulled the gas tank out last night. I didn't have time to pull the fuel pump though. I'll keep you guys updated on the rest of the progress.

redcj576 09-02-2009 01:31 PM

awesome work man! someday i want to get a Vortec engine :)

Travis1995 09-02-2009 01:55 PM

O thanks! I almost had myself convinced I didn't need a 5.3. :rolleyes:

fatwreck 09-03-2009 05:54 AM

The fuel tank is out.

Here is the stock sending unit and fuel pick up. It should work out well with the planned external fuel pump.

I'm stopping by the parts store today at lunch to get the plumbing for the pump/filter/etc.

Fernando 09-03-2009 10:19 AM

Awesome project! Will be following the progress!

jaywiz1977 09-03-2009 10:32 AM

looks good man!:2thumbsup:Will be following to see how this goes.Vortels are def the way to go,what year suburban did it come out of?

fatwreck 09-03-2009 10:34 AM


Originally Posted by jaywiz1977 (Post 7868909)
looks good man!:2thumbsup:Will be following to see how this goes.Vortels are def the way to go,what year suburban did it come out of?

It's out of a 2003 Suburban. It's DBW (drive by wire) and it has a return line for the fuel.

jaywiz1977 09-03-2009 10:59 AM

thats what i thought by looking at it,did ya get the pedal assy?also make sure when you put the fuel system back together,you use high pressure fuel line(the rubber) that system runs between 60 and 70 psi,and may blow out reg fuel line.Don't ask me how i know this,just trust me

fatwreck 09-10-2009 05:25 AM

Yes, I did get the pedal assembly. I haven't mounted it yet, but I'm sure I will soon.

I did use FI rated fuel you can see below.

Got the fuel pump in. It's really close to being at the bottom of the fuel tank. I can verify that tonight when the fuel tank goes back in, but that's what I remember when I mocked it up.

EDIT: 02/28/10 - Just an FYI...that fuel pump is in backwards. The jeep wouldn't start and I realized I wasn't getting fuel. I switched the pump around and I was good to go.

I used the factory 5/16" line as the return line and made my own 3/8" line with a combination of FI rated hose and hard line.

I know some people try to package the fuel pump and filter together, but I was having a hard time bending the 3/8" line without kinking it. As you can see, I ended up moving the filter towards the front of the vehicle. That worked out much better for me.

I need to find a P clamp to hold the filter in place. It's fine for now, but it's not secure.

I then ran the lines up the firewall. After I get the tank mounted tonight, I will know how much extra fuel hose I have and I can then run it from here to the engine. It should only take a couple of minutes.

wanabejeeper 09-10-2009 07:40 AM

NIce thread! great job!

elephantrider 09-10-2009 07:47 AM

does the weight of the v8 vs. the i6 make it
to where you have to get heavier springs to
hold it up ?

good work ! that yj looks pretty dang good.

fatwreck 09-10-2009 08:21 AM

It's been a little while since I read the info, but I think they weigh about the same. I can look it up if you really want to know.

The time now is 12:44 PM.

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