Hey All,
I'm changing my 91 F150 (302) from fuel injection to carburated and I have a couple of questions regarding the change over.

First, am i going to have to do anything to my ecm or coil or distributor?
Second, will the kickdown cable for the transmission work properly still?
Third, for my 302 what size card would be about the right size. i have a holley 600, would that be too much carb?

any advise would be much apprieciated. thanks
-Phill

 

Not sure on your first two quesstions, but a 600 should work just fine for you. I had a 570 on a 302 and also a 700 and the 570 worked just fine. the 700 was put on after i built it. Hope that helps some.

 

You will have to do something for fuel pressure. Fuel pressure on fuel injection is much higher.

 

I just remember reading on a mustang forum about a couple guys doing this change. I'll see if I can find out where it was for you.

 

Unless you like a lot of drivabilty issues, you'll need to change the cam. As I understand it though, Florida requires an emissions test. It won't pass if you are subject to it. Unless there is an extreme reason for changing to a carb, you need to know it is a major step backwards.

 

Here's a couple that I saw

http://mustangforums.com/forum/5-0l-...i-to-carb.html
http://mustangforums.com/forum/5-0l-...-question.html

Hope these help you out some.

 

labnerd- theres no inspection in florida that im aware of, and the reason im changing over is the previous owner did his own wiring and nothing electrical on the truck works all that well. i also just like the look and and feel of carbed, its just my personal preferance. also i want to put a snorkel on it, and i sorta think that could be easier with a carb. i mean my motor is kinda funky anyway. the guy that owned it before me took the egr out and there a blockoff plate there. the throttle cable is for a different vehicle and its to long and gets stuck a 1/4 throttle all the time. the electric fan is wired to the same power source as the front speakers so it only works when the radios on. this is what im dealing with. so im trying to take out as much elctris stuff as i can and then start over. -thanks for the advise

kingfish51- i was told that i needed a regulator before, but im not sure what psi i need. do you know? i dont want to buy the wrong one.

 

how bad do you think it will be??? and at what rpm range? is there a cam that you suggest?

 

Not sure, but will be very low compared to stock EFI. This is just a guess, but I think something like 8psi. Don't take my word for that though. You may also have to do some plumbing to get the excess fuel to return to the tank. Otherwise yo0u would burn out the pump trying to always pump against th resistance from the regulator.

 

1. You will need a distributor form a carb'd 302. The camshaft material will determine the type of distributor gear you need to run. You will also need some type of ignition, like MSD or Mallory.

2. Depends on what type of tranny you have. If it is an AOD, you will need the Lokar cable/adapter.

3. Holley 600 will be fine. Use a plain jane Edelbrock Performer intake.

I would stick with the stock cam. It is "matched" to the converter you have. The absolute "biggest" cam I would run would be a stock HO cam from a 86-93 Mustang.

You are also going to need a different fuel pump. You will want something around 6 to 7 psi.

I have converted many fuel injected Mustang's over to carbs. I will say that for all out performance, a carb is generally faster/makes more power.

For a truck...I would stick with fuel injection.

 

ok so i think im about ready to get started. i have a performer rpm intake, i got the lokar adapter, a buddy gave me a newish edelbrock performer carb, which im gonig to use instead of my holley, its a 600 manual choke. my crank, cam and valve train are all pretty new. I replaced them about 6 months ago with new ones from summit. i got an adjustable regulator from aeromotive (if i set it low enough will that eliminate the need for a return line???)

I think I am just about ready to get started.
My main 2 questions now are -

1. would a new fuel pump be better than a regulator?
2. the coil in it wont work? its an msd. its not a box, its a msd tfi type coil

thanks in advance for your input

 

A new mechanical pump is cheap and it eliminates the need for a return line. Plus it is quieter by a ton. If you go with the aeromotive regulator, you MUST run a return. The problem is the stock F.I. pump runs around 35-40 psi. For a carb you need 6 to 7 psi and volume plays a part also.

You need to get a distributor from a carb'd 302. Just go to Autozone and get a new one, probably $70 or less. You will need a duraspark box or an aftermarket ignition. TFI is computer controlled and you are doing away with that.

What heads are you running? Casting numbers?

 

ok so heres where i'm at, its been a busy few days at work but i have pics of my status.

 

600 holley will be just fine. You will need a different dizzy! I strongly suggest buying an HEI style. You will also need to run a different fuel pump, and remove the stock junk out of the fuel tank and replace it with a siphoning hose. Not sure about the kickdown cable, I have only work around a manual tranny.

 

dude them HEI distributors are but ugly hanging off the front of ford motors. Ford makes a decent electronic distributor and junk yards are full of them.