LS into a F350

Vigo wrote: Well, i mean it doesn't sound like it would be much cheaper for him to piece together a factory PCM/harness than a Microsquirt setup considering he'd have to buy them, modify them, and then have them modified some more by someone who owns some other stuff he doesn't own. The advantages of the stock stuff shrink a bit vs other options when you have to spend similar money either way.

The best way of doing a GenIII swap is to get the engine, harness, and underhood fuse box. You give the fusebox accessory power, ignition power, start signal, and a couple other things that I kinda forgot, but certainly NOT on the scale of a complete chassis re-wiring.

If you grab a GM instrument cluster, that gets you all the gauges in one get-go. It talks by CAN to the engine computer, and everything goes through the PCM anyway. Including the fuel gauge. (Which is where the tricky part is since Ford is a different sender species from GM, not insurmountable though)

There's no reason it shouldn't be done with all OEM electronics, that is the way to minimize headaches. Heck, add a vent solenoid, and you'd be able to keep all of the emissions stuff too. There's no excuse not to run full emissions on a stock engine swap other than "I'm too lazy to connect two more wires and add a hose".

LS based wiring info

Brendan can turn off whatever you need regarding the PCM

There's no PCM tuning involved in this swap. Just make sure the MAF is treated correctly (IIRC, something like a 6" length of straight 4" pipe and the PCM will be happy as a clam. Turning off the VATS, rear O2 sensors and the like is about as complex as posting to an internet forum - they're just checkboxes in the tuning software

Gauges are easy, you should be able to move the Ford temperature and oil pressure sensors over to the Chevy mill with an adaptor or two. Fuel doesn't need to go through the PCM, it can stay as Ford designed it. Tach is one wire. Speedo can be more of a challenge if there's no way to do a mechanical drive.

In reply to Keith Tanner:

If he's keeping the T19, wouldn't the cable not change?

The best way of doing a GenIII swap is to get the engine, harness, and underhood fuse box. You give the fusebox accessory power, ignition power, start signal, and a couple other things that I kinda forgot, but certainly NOT on the scale of a complete chassis re-wiring. If you grab a GM instrument cluster, that gets you all the gauges in one get-go. It talks by CAN to the engine computer, and everything goes through the PCM anyway. Including the fuel gauge. (Which is where the tricky part is since Ford is a different sender species from GM, not insurmountable though) There's no reason it shouldn't be done with all OEM electronics, that is the way to minimize headaches. Heck, add a vent solenoid, and you'd be able to keep all of the emissions stuff too. There's no excuse not to run full emissions on a stock engine swap other than "I'm too lazy to connect two more wires and add a hose".

You're right, it would be easy to 'slap it together'. It would be easy to just lay a harness from another truck in the engine bay, zip tie it so it doesn't fall on the exhaust, jam an instrument cluster into the 1980 ford dashboard and wedge it in with folded up fast food receipts, have a forever CEL with 6 codes for things that arent connected, and call it a day.

Maybe i shouldn't be disparaging about this because that's probably the exact type of build OP wants to do, but i was talking about the wiring work that's needed to make something look not half-ass when you swap a harness into a totally different body. Most of it isn't 'necessary'...

Also, a vent solenoid is not an EVAP system. You would also need to mount and wire a fuel tank pressure sensor and somehow fit a cap that allowed the correct amount of vacuum before letting air in so the system wouldnt fail the leak tests. Or swap in the whole GM tank which means possible mounting and filler neck hassles. Maybe none of it is hard, but then again neither is correcting some wire lengths to make your engine bay not look like crap.

The GM engine harnesses are quite self-contained. They integrate nicely into a different vehicle because of this - all of their wire lengths are perfect for the engine and you don't have any stubs where you hacked off a big chunk of wire going to an old body control module. Sure, the fuse box might have a GM logo instead of FoMoCo, but that's not exactly half-assed if you pay attention to where it goes. Any CELs are simply addressed by checking the appropriate boxes in HPTuners.

Chadeux, you're right. I somehow thought he wanted the trans out of the donor truck as well. If he keeps the original trans, then there's absolutely no need to mess with the instruments. All he'll need to wire up are things like the alternator light, a light for the CEL and a wire for the tach.

Changing the fuel tank is completely unnecessary, although if the take-out motor is carbureted then you'll need a high pressure fuel pump and a regulator. The Corvette filter is a nice combination of regulator and filter, so that's easy to solve.

Yah, the only reason an OE wiring/computer install could look and act hokey is if you unclipped it from the many preexisting, pre-engineered engine hold-downs and split the loom open for some unfathomable reason.

So apparently here in the frozen north, I'm getting quotes of 450 to 600 to "shut off what I don't need".

The distributor for hp tuners is only 680ish, and I end up with 8 credits (enough for 4 pcm),

So i'm thinking i'll get it and if it is as simple as some people say (check marks in boxes)

My side gig is finishing project that other's start/cant finish. This might work out to an advantage somewhere down the line

It really is as simple as people say. If you want, you can download the trial version of HPTuners from their website, which comes with a bunch of sample stock tunes, and play around with them. You don't need to spend credits to read a tune, just to write a computer or save a tune you modified.

Disabling VATS is literally as easy as checking "None" under theft control. (The other options involve where the antitheft module is in the car - body control, elsewhere... all you care about is "None") The other things are slightly more complex but nothing you wouldn't be able to figure out in ten-fifteen minutes. Plus there are heaps of guides available online.

You'd probably also set fault codes for anything related to vehicle speed (which includes idle control!). You could deal with this, I think, by starting with a manual trans tune, which would require burning another two credits because of the way the credits system works (the tune has a PCM serial number attached, it is the serial number that you are registering) OR you could just disable any check engine light faults that pop up and probably won't make a difference either way.

Disclaimer: I have never done any tunes on manual trans cars. I'm probably wrong to some degree but five minutes' learning away from being right.