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5.3L Vortec V8 Conversion

Frank Z

NAXJA Forum User
Location
Colorado Springs
First things first.
Please help me keep this as a TECH ONLY thread. If you want to debate the merits of different engines please start another thread. Hopefully we can all learn a little as this progresses.

I'll do the best I can to answer any questions regarding the swap.

Thanks.

This is my latest upgrade, a Chevy V8 stuffed into a 97 XJ. here's what I started with:
2003 5.3L
Complete harness for the engine, tranny, Drive by Wire throttle, peddle assembly and the thru the firewall harness for the entire dash.
All Fuse and relay blocks
All front end bolt-on's
Starter
All fuel lines
All electronic contol modules

4l60E 4x4 Transmission, flexplate, torque converter, and transfercase adapter (tailcone).
All tranny wiring including the NSS (aka PRNDL Switch)


After much research I opted to buy a motor mount kit from Novak Conversions. This saved alot of time and was well worth the money.
At long last....PROGRESS!!!!!! And a few pictures.
This is what I started with this morning. The first order of the day was to remove the Evap Canister, A/C lines at the firewall and accumulator, and the hoses for the heater.
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Next up was the original motor mount brackets. I pulled the OEM brackets and installed the Novak adapters.
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After seperating the tranny from the engine I installed the motor side of the Noval kit.
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The first attempt at dropping the motor in didn't go to well. The OEM manifolds are just to big.
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I pulled the motor back out and removed the exhaust manifolds and tried again.
SUCCESS!!
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With the motor in place you can see that there simply isn't room for the stock manifolds. I'm going to research some block hugger headers and will post up which ones I decided to use.
Passenger side...
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A few pics with the wires moved off the top of the motor.
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The tranny is in and the tranny mount is actually about an inch or so forward of the crossmember. Not sure how this development will affect the crossmember and the transfercase location.

Another development that I wasn't counting on was the transfer case itself. I procured an NP231C out of a S-10 and assumed that the mounting would be the same as my current NP231J. Simply put...It Ain't! The "C" has 5 mounting holes and the "J" has 6. It looks like the "J case bolt pattern matches the 4l60e tailcone. At this point I'm not sure if the "C" input is 27 spline or if the diameter is correct to mate with the tranny. More research is required, though I thought I had this covered already.

Just to muddy the water a bit more, my 4L60E tranny does in fact have a 6 hole pattern, not the 5 bolt pattern that is commonly found on the 700r4 (or 4l60E tranny that was used in the S-10).

Cross member modified to accept Chevy transmission mount, transfer case linkage rebuilt to clear new tranny.

Played around with stock exhaust manifolds as well. A little cutting here, and little grinding there.....I think I can make 'em work!!!!! Been doing copious amounts of reading on cutting and welding the cast manifolds and so far it looks perfectly do-able.
 
Here's what I finally ended up with:
The case is the original NP231J from my heep.
Front output is from an Dodge NP231D t-case.
The main shaft is from a mid 90's NP231C

I used the chevy input since it's a 27 spline and matches the tranny. I also robbed the wide main gear, reluctor ring, VSS, and tail cone from the chevy t-case.

The clocking ring is all home build stuff using a 8" O.D x 5" I.D. x3/8" thick steel donut.

While I had the case apart I also cut about 3/8" off the tail end of the rear output shaft to get to the softer steel. I then drilled it and will tap it in the next day or so. I'll be installing a flanged SYE and then I can deal with the driveshaft.

Made a lot of progess on the wiring as well today. Hopefully I can get the PCM mounted tomorrow and start shortening some of the wires for it too. Buying a harness would most certainly have been easier, but going this route I'm becoming intimately familiar with the Chevy harness. Yes, thats a good thing.

Did a little research and measuring at the parts house a few days back and found that a GM fuel pump (from the same model and year as the donor rig for my engine) will fit in my stock fuel tank. The upper ring will need to be widened by either plastic welding another ring onto it or sandwiching between two pieces of stainless steel. I'm thinking that the SS option is the better of the two.
 
Decided to modify the OEM manifolds till i can get the Novak headers. Started by removing the heat shield and cutting off the portion of the casting for the EGR tube (no EGR on my 03 engine). I also cut off the flange and a 1.25" section of pipe between the flange and aft exhaust tube.
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With the additional casting material removed the manifold fits.
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I'll have to cut out the old upper control arm mount from the frame rail to gain a little for clearance for the down pipes.
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I'll weld the manifold back together with a different flange angle and then start on the Y-pipe. I spoke with Eric at Colorado Welding Supply at length about welding it and he provided some excellant advice. Thanks Eric!!
I decided that although piggy-backing 2 PCM's can be done, at some point the OEM XJ PCM was going to come out anyway so I decided to stretch out the schedule and go ahead with a single PCM. The main obstacle to overcome was instrumentation. Adding a full set of quality aftermarket gauges simply isn't in the budget, so I had to go a different direction. I picked up a gauge cluster for an 03 Tahoe and am in the process of getting it mounted. Once it's its installed and connected I'll have no need for the XJ PCM and gauge cluster. (Check out my ad in the classified section)
The XJ cluster is on top and obviously a bit smaller that the GM cluster.
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In this pic you might be able to see the other major difference between the two. The XJ cluster is wider (from the front of the cluster to the rear) at the top portion, while the GM cluster is skiny on top and fat on the bottom.
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This pic shows the wider GM cluster a little better. The problem is that with the thicker/wider lower portion on the GM cluster, the steering column cannot be raised to a comfortable position. Even with the OEM cluster mounting bracket removed the new cluster still sticks out too far along the bottom.
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In order to get the new cluster a bit farther into the dash I trimmed off approx. 1.25" of the plastic housing along the bottom and then removed most of the remaining curve from the sides with my Dremel.. A little more trimming was requires on the mounting flats inorder to get it past the ducts on either side. Although not in it's final position, the follow pic should illustrate the difference after trimming the new cluster.
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The plastic support/mounting bracket behind the OEM cluster was also removed and a new headlight/dimmer switch location will have to be addressed too.
I tried to remove the clear plastic lens from the cluster so I could reuse it after cleaning up the edges of the housing. That S.O.B. wasn't coming off in one piece no matter what I tried. No worries, Lowes sells thin Lexan.
 
Some more t-case info.
It's installed
The t-case has a front output from a 231D with a wide chain gear
The mainshaft, wide gear. wide chain, reluctor ring, VSS, input shaft (32 spline) and 4 planetary low range came from a 94-ish 231C.
The case is my original NP231J.
The t-case is clocked approx. 20-25Deg using a homemade clocking ring.
Linkage for the t-case has been shortened and the OEM XJ shifter works fine.
Still need to order a flange adapter for it.
The 6 bolt pattern for the t-case is not equally spaced at 60Deg between each hole so my first attempt at a clocking ring was a dismal failure. I ended up getting a Chevy gasket and used it as a template. This took some time since the gasket will only fit in one position.
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I also used the gasket as template for a second gasket. there's one on both sides of the clocking ring.
The stock GM power steering pulley had to be replaced since it comes extremely close to the power steering gear box. This was compounded by the fact that my gearbox is a wider Durango box that is also spaced inboard an additional 1/4" as compared to a stock XJ spacer. I picked up a smaller pulley (-3/4" in diameter) from a mid 90's Ford E-150 van at a local boneyard.
 
Slow progress, but some is better than none I suppose.
I pushed the rig out of the garage to free up some valuable space and took advantage of the nice weather and got started on the cowl hood. Basically a stock hood with a few stategic cuts. The filler pieces on the sides will be 16ga steel.
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After lowering the hood I quickly realized that the alternator and the purge valve were going to be an issue. Actually I knew this when I got started but untill I was standing there looking at it with the hood in place I didn't fully appreciate the "situation."
The alternator sits about 2" above the normal hood line.
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Slightly behind the alternator on the intake manifold is the Purge valve. It is higher than the alternator. I'm going to fab up a 90deg adapter for the valve so it really isn't a major issue.
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Without modifiying the purge valve and lowering the alternator about an inch or so, the hood is gonna look like crap. So I'm gonna be burning up my bandwidth looking for a bracket that will keep the alternator on the drivers side but allow me to lower it a little bit. If anyone knows of a good solution, please let me know.
 
lookin good frank keep up the good work
 
Great, I was hoping this would move over here, I forgot my password to LS1tech and was not able to comment over there.

A 2in cowl does not look too bad. It would still make me uneasy with the alt that high up just from a torque flex point of view. Hopefully you can work out a bracket to lower it down a tad.

I am torn between the simplicity and cost of the truck motor install, and wanting to switch to a car style intake and rails for more available horsepower.
 
Very nice. Even in stock form, that engine will move a lightweight XJ along quite well. If you want more power, the aftermarket is swamped with mods!
 
So if you wanted or were able to afford it, does Novak sell every last part to make this swap without having to fab a bunch on your own? I see the headers & mounts, but how about the hood, crossmember, alternator mount, etc. etc.?
 
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Just seems odd for Novak to offer motor mounts that raise it to where a custom hood is needed, unless there are other varieties of the 5.3 (I know there are many configurations) that don't have stuff sitting as high and don't require the hood mods. I like how you're doing it with the gauge cluster and just reusing all of the tahoe wiring. That's the way I'd always though of doing it, perhaps even with a custom dash to mount that gauge cluster to. Seems much simpler than trying to make the xj gauges work.
 
It will be interesting to see how you fit the gauges into the dash and make it a clean look. Are you planning on hooking up that trans temperature gauge on the Chevy cluster?
 
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