Conversions & Swaps LSX Engines in Non-LSX Vehicles
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99 ls1 into a 98 3.8 fbody

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Old Feb 28, 2010 | 09:09 PM
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Default 99 ls1 into a 98 3.8 fbody

Hey all I was wondering what it would take to swap my ls1 from my 99 TA into a 98 3.8 firebird donor car? The most concern I have is the wiring harness part. Would I be able to completely be able to transplant the wiring harness from my car into the 3.8 car? I know from searching around on the forum that it's most optimal to use a 98 ls1 harness but I would rather use what I have for cost effectiveness. I already know to swap the kmember, steering rack, radiator, and my fuel system or fuel pump.

Rusty
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Old Feb 28, 2010 | 09:11 PM
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when my car (98) got a (00') ls1, the 00' wiring harness needed lots of re-wiring
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Old Feb 28, 2010 | 09:21 PM
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So it's not impossible, just a huge pain in the ***?
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Old Feb 28, 2010 | 11:35 PM
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Does anyone have any tips for doing the wiring harness part or anything else in doing the swap?
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Old Feb 28, 2010 | 11:56 PM
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You will have to do some re-wiring on the Engine Harness..it can be done, just with some work involved..

The 1999 Harness is the better one to use.
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Old Mar 1, 2010 | 10:46 AM
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I think the connections on the engine harness that would have to be changed are the MAP and ECT pig tails, then you would need to re-pin the ECM Red/Blue connectors to match up with the correct pin for the 99+ harness.

Like everyone said, it is doable.. just PITA

If you have all of the 99+ body wiring, You can also consider converting the 98 body into a 99+ one by using all of the wiring (or what is needed) from the 99+ body (BCM, Dash/Gauges, etc).
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Old Mar 1, 2010 | 12:33 PM
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I was wondering if I could just pull the whole wiring harness and cluster from my 99 TA and putting it in the 98? Like a total transplant? Huge pita compared to just rewiring?
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Old Mar 1, 2010 | 01:30 PM
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That would be a little better cause you know it would work..
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Old Mar 1, 2010 | 01:39 PM
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I find it hard to believe it's much cheaper to swap a ls1 into these cars than to sell the v6 car as an offset and get a ls1 car. Is it really? The cars have just got so cheap...
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Old Mar 1, 2010 | 01:57 PM
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LS1 Cars are pretty cheap..then again it depends on how much you are spending for the swap.
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Old Mar 1, 2010 | 02:02 PM
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Well I already have a LS1 car, the problem is the cost of getting the bodywork, paint, and new front bumper done on mine. So I got a v6 bird that I'm probably going to be picking up for a couple grand. I'm hoping to sell the tranny off of the v6 bird, the wheels off mine, and see what a junkyard will give me for my TA. So that's why I'm considering doing this, cause I have my donor car. And the motor/tranny is already out of mine lol.
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Old Mar 1, 2010 | 02:15 PM
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ah well that makes it cheaper I suppose, but if it were me I would fix the trans am...when it's done you have a fixed trans am

when the swap car is done you have a ls1 firebird (aka ugly IMO) with more potential for gremlins

if anything I would part out the t/a and put the couple thousand cost of the firebird with that and you might end up close to the price of another ls1 car

don't expect more than $100-200 for your car with no engine/tranny from the junkyard
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Old Mar 1, 2010 | 02:27 PM
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Lol if you could see the poor state of my TA...there's not really much I could part off mine, considering I want to keep the whole drivetrain from engine all the way to my 9bolt rearend. I don't mind the look of the firebird, and I will take the spoiler off the TA and i got a WS9 hood that I've been hanging onto. I would prefer a TA just for the looks, not really concerned with the whole oh you just have a firebird. Yeah I just got a firebird with 450hp. Plus insurance should be cheaper...Bonus!
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Old Mar 1, 2010 | 03:57 PM
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not trying to be a downer, I just don't know the details I guess

I just despise the look of the firebird/formula...don't care what other people think about em either, so if you like it that's cool

I just thought lots of other stuff (steering rack, brakes, ect) were **** on the v6 cars too, power isn't all of it

If you already have the stuff it could be a good deal too, I was just curious
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Old Mar 1, 2010 | 04:07 PM
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Np man, everyone's entitled to their opinions. It's all good. I'll be switching over the steering rack, and I think the brakes have been upgraded. Won't know till tomorrow.
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Old Mar 2, 2010 | 08:02 AM
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Originally Posted by Sube
I was wondering if I could just pull the whole wiring harness and cluster from my 99 TA and putting it in the 98? Like a total transplant? Huge pita compared to just rewiring?
^^Do this. Everything will of course match up. Rewiring and repinning will suck. If you're not doing anything with the 99 cluster, use it with the 99 pcm and harness, especially if the 99 cluster will fit in your 98 v6 dash (I had to use a different dash for my 93 v6 Camaro when I did my swap).
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Old Mar 3, 2010 | 07:23 AM
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Another question I have, what about the mileage change? My new car has 187k on it, while my TA has like 85k. If I switch everything over will it read my TA mileage and if it does how will I square that with the DMV?
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Old Mar 3, 2010 | 12:09 PM
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**** ton of road trips, or find a different cluster with lower mileage?
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