I have a 91 F-150 4.9 I am interested in knowing if there are any carbouration manifolds to fit it, and if there are any hazards in converting an EFI engine to carbouration.

 

If you must convert your EFI to Carb. all you need to do is find a manifold from a 4.9L that was carbed. Any early 80's model 4.9L will work. That is just the start. You will have to find thottle linkage, kickown cable (if yours is an Auto), different fuel pressure regulator, and you will probably have to get rid of the high pressure pump entirely. I have heard of people running the low pressure pump then using a pressure regulator to drop it to a PSI that a carb can handle.

Of course that is just the start. You will need a different ignition, (one from a early ford would work (duraspark)), and distributer. This is of course all that I can remember right now.

Are you having problems with your EFI? The EFI system is actually relativly easy to work on. It just takes alittle studying to figure out what everything does. After that it is a snap. Switching to carb will not only cost you $$ in resale value but also probably net you less HP and less MPG (of course a properly tuned carb is close to EFI but how many carbs actually run right???). Another thing to look at is if you 4x4 at all, Meaning rock climbing and hill climbing, carbs will cut out at extreme angles. Causing it to be worthless and your truck to die. There are carbs now that don't cut out but they are $$$$$.

 

I think it would be cheaper for you and much better to tune up your EFI. EFI is much more efficient. Just my .02 cents worth.