Have a 91 EFI 300 I'm swapping to a carb using parts from a 66 240. Looked through these forums but had a few questions.

Seems the 240/300 is internally balanced, any issue then with using the crank pulley and flywheel from the 66 240? Manual truck if it matters.

Looks like most heads are interchangeable from these engines but the EFI heads are different with the combustion chambers. Is it worth trying to keep the EFI head, plug the EGR holes, and recurve the distro or just swap the 240 head over? I'm swapping the distributor from the 240 also.

Thanks guys.

 

This was recently discussed in another forum. Perhaps this link will help: FORDSIX PERFORMANCE ? View topic - Crankshaft Pulley

 

If you plan to run the 240 distributor you are better off swapping the 240 head on to it.

You will also need to swap to the 240 waterpump & pulley. The 91 will have a reverse rotation waterpump and a serpentine smooth pulley. Plus the EFI water pump is designed to use a fan clutch assembly.

 

I do plan to use the 240's distributor, but why swap the head? I read that the EFI head requires different timing for optimal performance, but will it be a big issue?


EFI's water pump was sticky so I already replaced it, figured it was easier to do now.

 

The EFI head requires less timing, the amount dependent on the load. But 8-10 degrees is of the right magnitude at WOT.

 

Do you plan to recurve the 240 distributor? If the answer is no then I'd run the 240 head. If you have no problem tearing down the distributor and taking some of the timing out of the centrifugal advance then run the EFI head.

If you just run the 240 distributor with the efi head as is, your engine could have some pinging under load. Pre-ignition may also be a problem.

Run what you want, it's your truck!

 

Put it together this weekend, went fine mostly but there were a few little things that came up, if anyone else does this. I had to mix and match on some things between the EFI and carb engine, bolts are one thing I remember. The motor mounts didn't fit exactly on the passenger side, bolt hole was about 1/2" too high. Used intake gaskets from the 66 and oil pan gaskets from the 91. Swapped oil pan just so there are no clearance issues, the dipstick will need to be modified now. Wanted to use the EFI exhaust but one bolt ear would not fit in with the 66 intake, would have required about 1/2 of it torches or ground off; used the OE log exhaust for now.


Still looking for a carb then I can fire it up. Electric fuel pump is on the way, may swap that 240 head if the pinging is an issue.


Thanks again for the help.