99mustang5.0

Hi I posted here before about this swap got a lot of mixed ideas about it . So I have a 99 mustang that I have put a 87 5.0 ho engine with a c4 into. Now trying to figure out wiring . I bought a 00 mountaineer for parts I am running the cam sensor ,crank sensor, and timing cover off it . I was wondering if anyone knew if the wiring harness from the mountaineer would plug in and work with the 99 body harness . If I'm not mistaken they run the same style computer . Don't know if it matters but I'm running the intake and gt40p head too.

89blackonblack

i dont know the answers to your questions but was thinking of doing the same swap so was wondering how hard it was to mount up the engine and tranny?

99mustang5.0

You can use the 95 k member or I believe the v6 one might work

jthorn9

It has to have a 100% compatable design, meaning the harness plugs and connectors must be identical. Aside from that it also depends on the specs that are preprogrammed onto that ECU. Remember 87/95 Mustang 5.0s were different from standard Ford 5.0s and did use different parameters on the ECU. If it does fit it may run the car, but rather or not it runs correctly would have to be determined.

You best bet is not to try to take any short cuts it will cost you way more money in the future fixing short cuts and going the right way. So in short, if it's not not made for an 87-93 5.0, which are different from 94/95 then expect it not to work.

Also don't forget your factory hood will not be compatable with the 87 5.0 design. It will sit too high inside the engine bay and will require a cowl hood.

99mustang5.0

We'll I have the ecu from a 00 mountaineer which is EEC-v setup which is the same as the 4.6 mustang right ? And I'm useing a distributer less ignition setup just like a 4.6 . I just wanted to no if I could use my 5.0 explorer engine harness before I go and spend more money on a 4.6 engine harness which I no will work . And the hood clearance won't b a problem I've already checked I have around a inch of Clarence.

89blackonblack

an inch of clearence may not be enough. if its more like 1/2 to 3/4 of an inch clearence you have to fingure in body flex and all that. mya not actually be enough clearence

99mustang5.0

The clearance should b fine on mine but is the engine harness out of say a 99 crown Vic the same as my 99 mustang ?

jthorn9

This would be the best answer you get here. Take some time and go to a few Ford specific race shops. Shops that specialize in extreme customization and talk to a few people. You will have to hit up more than one. You may wanna also find some old Ford Tech guys, people that's been with the company since the days of the 5.0 up to more moderate times. They will best be able to explain what will work with what, why it will and why it wont.

So many people undertake a 3.8L to 5.0L swap and end up getting way in over there head and have to wind up selling the car for little or no value. I'm not joking when I say that every week to every other week I see one of these "projects" on craigslist because the person didn't have enough knowledge or didn't take the right steps to make the project work.

The concept seems so simple, but the application is truely a very daunting task. What's worse is you're mixing Mustang and other Ford/Lincoln parts which just makes it that much more complicated. Remember the more complicated something becomes the more likely it is to have something major go wrong. Even the basic of basic swaps (IE 95 V6 to 95 5.0) causes people a lot of headaches. Not to mention (95 v6 to 93 5.0) which causes even more. Or the worst (96+ V6 to 93 back 5.0) because the technology changed that much in the cars in just that short time frame.

99mustang5.0

We'll I have a plan that should work just trying to get a engine harness that will work with the body . I have the chance to get true engine harness for cheap out of a 00 police interceptor crown Vic just need to no if it will fit my 99 mustang

jthorn9

Well a harness is just a harness, it'll fit in any car. Will it be an exact fit, no not unless it's made specifically for that body. But anything car fit by splicing. Is it easy, hell no, but it can "fit".