jarrettbailey

iTrader: (1)

Hi all! I am sure you will all get tired of seeing my posts on here b/c they are mostly because i am new to this and wondering about alot of it. This particular one has to do with the PCM and harness for my engine.

I am building a GROUND up '55 truck and the project is something like this:
55 truck with a short wheelbase (about 6" shorter than a short wheelbase) on a frame constructed from a late model s10 and a '72 chevy rear section and some fab work to boot. I have an LQ4 for the powerplant and an automatic tranny that a friend snagged for me. (not sure which tranny yet but I think it's out of a 04 pickup) rear end is a 12 bolt with 3.73's and positrac.

Now I am not yet 100% on what my LQ4 will be like when I get finished, but right now it is just a crate longblock. I think I may replace the heads with 243's and put in an LS6 cam. Probably going to run F Body accessories and an LS6 intake. (So far that's what it looks like). What my questions here are: what will I need the harness to be setup for? What kind of PCM should I find? What other information do I need to look into to understand this better? I know this is pretty vague info so any articles you can point me to, or advice you can give would be greatly appreciated.

12thstreetjunkman

iTrader: (16)

I wouldn't mess with the 243 swap, you would pretty much have the same thing, just get yours milled some. As far as pcm/harness. It really doesn't matter, esp if you are going to be changing things around (cam, intake) you will be needing some tuning done anyway. Both of the harnesses get modified the same way, if you end up with a car harness and truck pcm, you will need to do some pin swapping. The injector plugs are different, keep that in mind if you already have some.

budhayes3

iTrader: (19)

For simplicity, I'd get the PCM and harness from the same type of vehicle, whether it be car or truck, then you can modify it as necessary as you go along.

nonnieselman

iTrader: (10)

Since you said a LS6 intake, im guessing your goin to be running a Cable throttle?

If it were me, id look for a 99-02 Truck harness and PCM.

Ditto on the stock LQ4 heads, if they are 317s. They are the same as the 243s but a smaller CC chamber. Just mill them some and you pretty much have 243 heads.


If it helps, Lownslo06 put down 301hp/315tq to the wheels on a 04 LQ4 with just a LS6 cam and Tune. Thats thru a 4L60E and 22" rims on a Dyno Dynamics.