4.6 versus 5.0 and years of donor car

[nomads2000]

Hello,

Sorry to be redundant, I just saw a similar post and can't find it for the life of me.

The short and long of it: literally getting ready to hit "send" on the order form for a Mk4 base kit. My initial goal was a 95 5.0 to get the 5 lug wheels. However, after speaking with the FF reps it appears the 94 and 95 cars are a hodgepodge of sorts and are a nightmare to make work correctly (wheel offsets, width of the back-end, computers, etc.). I don't want the 4 lug cars, 87-93, because it's hard to find wheels/brakes etc. for them (all the Halibrand knock-offs are 5 lug). I, of course out of tradition and "look", want the 5.0 but it seems like the only benefit is really the look in the engine bay and/or getting a carb'd crate motor. The 4.6 with the FF rear-end, brakes, front A-arms etc. seems like a much more realistic and solid build and not so frankenstien.

So, thoughts? Yes, a 5.0 would be great, but from what I've read it appears a stock 5.0 donor has too many drawbacks from the rest of the car to really justify the lump.

BTW: I'm leaning towards the 96-99 4.6 cobra, 305 hp, 300ft/tq, 5 lug, Halibrands, race seats, upgraded 3 link suspension, FF rear-end and 4.6 donor kit.

Any feedback would be appreciated.

Thanks, Damon

[evvander11]

It's easy enough to swap out the 4-lug axles for 5-lug axles on the 87-93 rears...thats the route I went, however I ordered a complete kit. The only things I used from the donor was the 5.0 engine (completely rebuilt from bare block up), the rear end (again rebuilt but it was pretty clean it must have been a replacement because it had 3.55 gears in it which were not options on the fox mustangs), computer wiring harness, and some smaller stuff like the coil, in-tank fuel pump hanger, etc....

Actually, Factory Five sold me 5lug axles for like ~200 bucks? Not sure if they still offer them or not.

[gtfireftr]

5.0's are getting old (unless you mean Coyote), and if you get one be prepared for a complete rebuild. You can still find a good low mileage 4.6 for a decent deal. You can sell off many parts to recoup some cash. I have a 4.6 DOHC from a 2003 Mach 1, and it performs great, stops great runs fantastic. It is all up to you.... JMHO Good Luck

[Perl]

Damon,

Below are links to previous topics about the subject that might help you. It’s a tough decision so take your time. The first link has topics that also have links to other topics so don’t miss those.

'87-'92 Donors - any major pros or cons for any year?

Does year matter?

[ShelbaToast]

I used a 96 and between the donor and kit had to source almost nothing. With the stock '96 axle the widest tires I can run are 295, but that's plenty of tire for the '96 cobra motor. You'll probably want to get a gauge kit but I used the donor gauges (took a lot of work) but the 96 is a very complete package from a donor.

[bhuff]

The 4 lug issue is pretty much a non-issue. You can swap to 5 lug rotors easily using mark VII/SVO rotors. The rear end is the same thing... you can grab axles (new or used) for the ranger/aerostar, both from the drivers side of said vehicle.

I would argue there are many advantages to going the 96+ route. You will get better brakes all around, disks in the back even. You will also have the option of keeping the traction control and ABS if your donor is so equipped.

[TerryDactyl]

All are fun. One advantage with new donors is that they are a newer design. The electronics/PCM get better and better. I stripped a S197 donor with strategy not to cut a single wire. First time I hooked the harness back up in the cobra hanging on the side of the car...she fired right up.

[Hunter 2]

4.6 motors from the years you like are not an easy install. Similarly the rear end of the 99-04 models will need to be changed to the 87-93 rear and the axles changed also in order to fit the wheels that come with your kit. Those nice fat 315 wheels wont play nice on the axle you described without mods. So no matter how you slice it, you'll be having dinnner with Frankenstein. I love the look of carbed engines but they are generally more than I want to deal with and horrible on gas. I had a nice carbed motor I was ready to pull the trigger on but changed my mind as I don't need the headache and I actully like to drive my Cobra...ALOT. Good luck with what ever you decide.

[vtcobra1]

Iv'e got a stroked 347 with a 650 holly and it running around 450 hp and on the open road I get 24 mpg. Iv'e driven from Vt. to Va, race track back when FF had their meet down there, and so I had a good chance to make sure the mpg were accurate. Love it the way it is.In 56,000 miles I have never touched the carb!!!!

[Art Cuesta]

No one usually thinks about the wiring of their build until much later in the build but it's worth giving some considertion to at this early stage.

The early 5.0's wiring is getting old, builders have complained about using 5.0 wiring since I first started working with Roger Stine back in Jan. 2000. And yet to this day (finished 3 5.0's last year and 1 this year) the early wiring is still out there doing it's job without any special attention. If you go this route check the wiring for condition (broken wires and burned up ignition and headlight switches ect). Normally once you remove the split loom and tape the wires are fine.

If your going early 5.0 with a carb then I would suggest using a aftermarket chassis harness (Ron Frances, EZ Wiring, Painless ect) with all new wire and and fuse panel.
If you go EFI and want all new wire you can use the Ron Frances from FFR and buy from RF a new engine wiring harness that plugs right into the chassis RF harness.

If you go 4.6 then the wiring basically divides into 3 groups - 96-98 Mustang 4.6, 99-04
Mustang 4.6 and 05-09 Mustang 3 valve 4.6.

The 96-98 Cobra 4.6 is the preferred engine in this year group. 4V and a simplier fuel system than 99-04 that more readily adapts to aftermarket fuel pumps if planned.

The 99-04 Mustang 4.6 are all being used - GT, Mach 1 and Terminator - take your pick.
The wiring more complicated than the earlier versions with the incorporation of the FPDM (Fuel Pump Driver Module) and FRPT (Fuel Rail Pressure Transducer). Easy way out on the fuel system - use the Mustang fuel pump which requires the Mustang main body harness which contains all the fuel system wires with FPDM and inertia switch from tank to correct connector to the PCM harness. If planning a aftermarket fuel system with these years plan on having it 'tuned' to 'dial in' the conversion for the PCM.

The 05-09 Mustang 3V 4.6 are a even more complicated system throughout (example: three connectors for fuel tank instead of 1) but they have been used successfully. I'm doing one right now for a project my tuner is doing. Same thing for the fuel system applies as 99-04.

Aftermarket (Detail Zone, ISIS) wiring system are availiable and have been used successfully so if your budget allows thats another option

Many builders with 4.6's only get the engine and computer harnesses with their 4.6 but your short the fuel system and Data Link Connector/OBD II diagnostic port wiring from the main body harness and dash harness which your going to have to do something about.

If your new to this keep your build simple and basic and don't go overboard on aftermarket products that have to be wired in above and beyond what a basic build would require. You want to finish your Cobra and have fun with it - not drive your self (or me) crazy figuring out how it hooks up and where your going to get the power from.

I've seen the new Coyote 5.0 and Control Pack (Sweet but Expensive). Really looking forward to seeing the complete Coyote Mustang wiring system that comes out of a Mustang and seeing what I might be able to do to simplify that wiring for use in a FFR kit or where ever else they transplant to....

Art