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putting an L67 into a '99 GT few questions

C

ColeTrain84

New member
Ok i got a line on a nice lower mileage L67 from a '97 with everything from the oil pan to the S/C. Doesn't have a harness but has all the sensors, brackets and all that. Also missing the coils but has the bracket. I know i'll have to get my PCM tuned for the swap and i'll need an MAP plug/extension. What else am i gonna need to do to complete the swap? Someone mentioned bolting my stock 3.8 flywheel to the L67 so it mates to the GT trans as well. I'm just covering all my bases before i dig into the swap. I've removed and built a couple L67's so that part i'm confident about it's just the conversion i'm not 100% sure on everything.:th_thumbsup-wink: Thanks ahead of time

*** Car that it's going into is a '99 GT coupe w/ 62k miles
 


What's wrong with the L36 in your 99? Top Swap? :D

97 is a unique breed. You'll have to plug the vacuum on the port of the supercharger behind the BBV and get a new Vac tree for the top I believe, but not sure regarding that... Other vacuum will be tweeked to work, but nothing major.

Your harness will work fine. You are correct regarding the MAP sensor adapter. When You hook it up make sure it's right. LOL Mine outer terminals were swapped. went ABC on my stock MAP plug to CBA on my adapter. I had to swap the outter two, but just my $.02 on that. I might have just got fubared one..

Your BBV solenoid will need a harness if you run it which will have to be wired into the PCM. I have heard of people removing the solenoid all together and having the rear vacuum port off the BBV open and run the BBV purely off vacuum. I've done this on mine, works fine. I believe the solenoid just controls boost while TCS is on.

You will have to use your GT flex due to the L67 flex torque converter holes will not line up.

Your Evap routing will be different. Evap solenoid on the GT is on the front, GTP is on the rear. Might just want to leave your GT EVAP solenoid and let it lay on the front of the motor like a top swap??

Your L36 ICM and coils should work fine on the L67

Might be it.. at least a start.. :D
 
Cool thanks for the heads up on the MAP. i knew the '97s had some unique stuff to them but in general they are supposed to be the same minus the vacuum lines and whatnot. The L36 is fine but i had a GTP at one time and loved it. Nothing against the 3.8 N/A but i miss boost :D I will sell the L36 for way more than i'll have into this L67 swap lets just say that :D
 
The reason i'm not doing a top swap is because i personally would much rather swap the whole engine rather than do all the work of the top swap. I've pulled L67's before and it takes me a couple hours to get them out. Where it would take me alot more time to get the top swapped and the rest finished. Just a personal preference. I'll have to see if i can track down a vacuum tree or a diagram to build one. As for the BBV i may need more info on that if anyone has it so i can figure out what i want to do with that aspect of it.
 
I know exactly what you are going through, did this myself a month ago except it was a 2000 L67 engine pretty basic swap minus the wire adapters you need, they weren't hard to install just gives you that scare since it is t a basic swap and have to mess with the wiring which I have no problem with but that is the scary part.
 
i'm not so much worried about wiring, i do wiring of systems in vehicles for a living but it's mostly trying to find schematics on what exactly needs to be done :D
 


97 isn't overly unique, there is an extra piece in the evap systsm and a vacuum tree. Beyond that the majoirity of the differences were wiring harness and pcm. Which is only different from 98+.

Stick with your current harness, change the map connector
Get the pcm tuned for it
Swap the flex plate
Use your 99's evap setup instead of the 97's since this is what your car is already setup for.
Swap your 99 alt bracket and alt onto the motor.
 
Yes make sure you have YOUR original GT pcm tuned for the GTP so it will have no issues communicating with your BCM...
 
Thanks guys. i found a local tuner to do the tuning and will be using my original GT PCM and just having the L67 tables uploaded and do a little tweaking and go from there. I'm gonna keep it as stock as i can for now minus maybe an intake...
 


Dont swap the flexplate, dremel the one you have to fit the smaller TC. I suggest against the HD upgrade.

Swapping the PCM for a GTP is a BAD idea. The best method of top swap is to use a GT file, DONT swap the map sensors (use the 1 bar), and adjust a few of the fueling tables to work with boost a bit better.

ZERO wiring changes are required, run the BBV in stupid mode (hook non boosted vacumn to the top of the valve, leave the bottom open) and it works the same as stock.
 
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