lq4 in a 98 trans am

ls1ta98

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Hey ppl how hard is to put an 2003 gmc 2500 lq4 317 heads on a 98 trans am
 

lastls1

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It bolts right up. All the parts and mounting areas are interchangeable
 

lastls1

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Wait are you talking engine swap or just swapping heads? Either way the heads will bolt right up as well. The 317 heads I believe will change your compresion ratio though
 

willizm

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If swapping heads it will drop to approximately 9.5:1. If swapping the motor it is identical.
 

willizm

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Swapping the motor what about harnes and computer from the lq4 motor
You should be able to use your existing ls1 harness and PCM. I haven't done the swap myself, but that is my understanding. Anyone else have insight?
 

Lead Pipe

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LQ4's in Trans Am's is race car shit. It will swap right in and bolt up no problem. You have to run your T/A intake, oil pan and accessories. Harness and computer is all the same.

A couple things is you have to drill and tap an extra hole in the block to mount the PS pump or alternator, I forget which. Also If it is a 99 or 00 LQ4 with the iron heads the crank is 1/4' longer and won't mate to your trans.
 

ls1ta98

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I dont have the harnes and computer from the ls1 car just the one from the lq4 motor
 

Lead Pipe

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You will need an f body harness. If it's a 98 T/A I would look for a 99+ PCM and harness. They can be found on tech pretty cheap. Unless you want to cut up the LQ harness and run it as a stand alone. The f body harness will have all the provisions for the TCM and BCM.

I just noticed you said 2003 LQ4 so you're good on everything lining up and plugging in.
 

lastls1

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So am gona need a new trans?
Just like all the engine components the transmission will bolt right up to the rear as well. Assuming 4L60 or what not

Edit: If you are talking like a truck 4L80 then you need a different driveshaft compared to the stock Fbody one. Shorter I believe. But Will would know more on that
 

Lead Pipe

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So am gona need a new trans?
No, do you have a 4L60 or T56? Either will work.

What I'm saying is a harness from a 2003 truck will not just snap into an Fbody with out modification. The easier way is buying a 99+ fbody harness and PCM.
 

Smokinhot

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Everything that [MENTION=3061]Lead Pipe[/MENTION] has said is spot on.

On a side note, better get that 4l60e built. It will not last behind a 6.0.
 

Mr_Roboto

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Is it an auto or a manual? Is the car original or was it tweaked? If it's original it's a 60E otherwise it could be damn near anything from a 'glide to a 6L90E
 

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