Mylesofsmyles

I don't really know where to post this, so if the Mods think this thread is more suitable, please move it...

I'm planning a V8 swap for my 75 Datsun 280z and 79 Volvo 242...though one at a time, lolz. Since I can't afford an LS3 and an LS9 for now, I thought I'd start small and get the grunt work done...swap in a cheapo Vortec 4.8 or 5.3 as those can be had for under $600...it'll leave me plenty of budget for all the other parts I'll need like the engine and trans mount brackets, upgraded fuel and cooling systems and my T56.

My understanding is that with an LSX there are automatic and manual specific PCM's and engine wiring harnesses. Considering the Vortec engines came out of vehicles that, as far as I know, were all automatic, what am I to do about my PCM and wiring? I'd assume the LSX manual specific wiring harness will work fine, but which PCM am I to use or can they be reprogrammed?

BLK02WS6

iTrader: (2)

Yes, a manual specific harness is what you want. And yes, the PCM can be reprogrammed... the best one to get is the part number that ends in 0411.

Mylesofsmyles

cool thanks for the info...so i'm right in thinking the vortec and lsx harnesses are interchangeable? as for the pcm...i'll use the one that actually came with the vortec and reprogram that, right? just want to be sure for when i go parts hunting.

BLK02WS6

iTrader: (2)

The differences you will find between the truck/car (T56) harness and engines will be in the injectors and throttle body. Those differences will all depend on the year and what you plan to have in your swap... The truck injectors use different harness connectors than cars - that can be overcome with pigtails that are available, or change the injector plugs on the harness... depends on which injectors you are gonna use and how you want to handle that. As long as you are going with a cable throttle body, you can just get a harness from a T56 Fbody... If you want drive-by-wire, you would need to find a T56 vette, or Caddy... Make sense?

Mylesofsmyles

yes, thanks...this makes a lot more sense to me now. I was thinking I'd have to get a kit from painless wiring or similar, or have someone custom make me a harness, but if I can just gank one from a t56 f-body than SCORE! so i'll need to splice over the old injector and tb connectors to the new f-body harness...just as simple as it sounds?

BLK02WS6

iTrader: (2)

Well, not as simple as yank it off and throw it in the swap car LOL! There will be work to do as far as fuel pump, fans, etc... If you want totally plug and play, you may want to look into a custom made harness, speartech, or painless... Are you going with the truck injectors/intake? which type TB are you going with, cable or DBW?

salemetro

iTrader: (5)

I know a guy who's an electrial engineer that can set you up with the harness (custom made) that you need for roughly $300.00...and NO, it's not me LOL. They are typically a simple 5-wire installation. He makes standalone harness for the following engines:

Duramax
Ls1, Ls2, Ls6, LS7
Lt1
TPI
TBI
Vortec
5.0 ford and others
Cummins diesel
Chevrolet, Ford, Dodge

He did the final harness integration for me on my own vehicle, and does work for some big-name companies as well. He's good at what he does.

PM Me for his tel# if you want it.

Mylesofsmyles

dunno about the tb just yet...cable sounds easy cuz I won't have to custom fit a new pedal...what are the perks to dbw? probably going to stick to the truck injectors and intake for now...unless someone's got input on that for me. I had my heart set on an ls3 for the datsun and someday, somehow a ls9 for the volvo...figured I'd rough it with a 4.8 and 5.3 until i could justify the big money power plants. i'd assume there are some higher flow options that i could replace the truck injectors and intake with, but like I said, i'm just roughing it so not really trying to put money into a powerplant I'm not keeping.

BLK02WS6

iTrader: (2)

Cable is easier... personally I don't like DBW. The truck intake fitting under a car hood is my only thought... they make good torque, so keep it if you can fit it.