86beast

So I have a 1986 Mustang gt with a 5.0, Ive heard good and bad things about this motor, first thing I have heard is that I can't swap cams because the pistons are true flattops and will hit the valves, is this true or false, and also I wanted to swap from the speed density fuel injection setup to something more easily tunable and managable, so I wanted to go carb setup. What all would I need to do to make that a reality, or is there something that would work better, its not a daily driver, more of a weekender/track car. Many thanks

mattdel

Going TO carb is easy mode. Carefully (or not) rip the wiring out of the car, replace the intake with a plenum + carb, tune it and drive. You'll need to dramatically lower fuel pressure if you plan to keep the in-tank EFI pump, otherwise you can get timing covers that have the opening for a crank driven fuel pump. (stock cover might even have the hole?)

The piston thing... ehh.. you can get away with camming it, but you'll have to do some number crunching to figure out ideal duration @ max lift, etc..

86beast

You can't just rip out the wiring, some of it has to stay for distributor and guages and everything else, plus what about the computer, wouldn't it send wrong signals to the ignition?

SmallblockPower

Keep the ignition wires and gauge wire clusters you want. I'm doing the same thing with my car, except I'm going to a 347 Stroker.

86beast

im close to just saying screw it and swap for a 351w

SmallblockPower

Make sure you can find engine mounts and a bell housing that will fit

86beast

I've seen kits to do it, but that still doesn't tell me how to switch over

SmallblockPower

make everything mechanical. you will need a new lower intake plenum as well as a carb, and you will have to change throttle linkage. you will most likely have to buy a kit for the linkage but the intake you will have to choose each piece, you wont need a PCM, for anything, all a PCM controls is the fuel mixture, and you wont have electronic fuel injectors. you will have to do something about the fuel and once again they make a kit for that as well. you may just have to search for it. But pull the wires that run the ignition, O2 sensors throttle and just about everything else. make sure you save the temp sensor wire cluster, you will need that later. but just think basics, you need headlights, keep those wires, lol, you don't need anything that has to do with throttle positions, o2s ignition. but basically you can take a look at where the PCM is mounted on the passenger side by the feet. disconnect that then just start disconnecting the wires and remove it through the rubber grommet that the wire harness goes through.

jojobanks

the main things you'll need is a carburetor (probably something like a 600cc 4 barrel) and an intake manifold to fit.

If you're keeping your electronic fuel pump, you'll have to get a fuel pressure regulator to lower the pressure to the carb. Or you can change to a mechanical pump, but that might require a few more modifications.

not sure, but I believe that by 86 they started running electronic ignition management as well. Check around your crank wheel for a sensor. If you have this then you'll have to change to a different distributor or buy an aftermarket ignition control system.

You'll need a new throttle cable. These are pretty easy to find and a pretty straightforward install.

plan on eliminating the pcm all togeather. Anything that is wired through that you'll have to wire up directly. Pretty sure this includes your speedo, water temp gauge and your tach if you have one stock. Honestly it might be better in the long run to plan on re-wiring the entire drivetrain. It sounds a lot more complicated than it is though.

other than that there's really not much to it. The most expensive items are the manifold/carb and fuel pressure regulator. You can do the whole swap for around $500 using all brand new stuff.

My89Gt

i did the swap last summer. Had to buy a carburetor, intake, fuel pump, distributor, coil, ignition box, and some switches. You can't forget your air cleaner as well. On the fuel injected cars you have to put your pump on a switch, because the car won't register that its running so the fuel pump won't continue running past a prime. I put fuel pump, ignition box, cooling fan on switches, and used a push button start set up. I wouldn't use the stock in tank fuel pump. I dropped my tank, and pulled the pump out of the hanger and replaced it with a piece of hose on the hanger assembly so that you could be sure that its low enough to suck the fuel up. I used an inline fuel pump and mounted it where the stock fuel filter was. (also put a different fuel filter in plus a fuel filter on the pump.) All of the ignition was msd (pro billet distributor, blaster 2 coil, 6al ignition box) . Carburetor was a 600cfm edelbrock performer, air gap style intake (pro comp), mr. gasket air breather, k and n air 14x3 air filter. I know a lot of people claim the computer isn't necessary, but seeing as its your body control module, you have to keep it wired in for your lights. There is a big square plug that unbolts that is on the passenger side of the car. Just take the harness out from under the hood. run new wires with aftermarket gauges for your oil pressure and water temperature gauge. I also ran fuel pressure gauge and oil temperature, but htey aren't necessary.

So complete new fuel system, ignition system, and gauges should be used. You can use your speedometer, and I used an autometer monster tach as replacement for my stock one. I would be prepared to spend some cash. Because a good carb alone is gonna run 250-300 alone for an reasonable street carb. looking at just under 500 for an intake and carb alone. 150-200 for distributor, 160 for an ignition box, 40 for a coil, 40 bucks per gauge, fuel pump varies depending on what you want, about 20 dollars worth of switches, 30 for air cleaner. and nobody has mentioned gaskets yet either. Intake gaskets are pretty cheap for 302s. I think i paid like 12 bucks for mine. I would probably run a cheap regulator too even with a lower pressure fuel pump.

Sorry to write a book, but hopefully its helpful