I hate to start this thread for a few simple answers but I've been looking but can't find the an answer to one of my questions. TIA for all the help. So here it goes I just recently purchased a 1991 F-250 4x4 supercab 7.5l with the E4OD. After a few hundred miles the shifts became weaker and weaker. Long story short took it to the shop and they said it needs a transmission rebuild. Quoted me 2800 that I don't have. Engine runs great and I would like to keep this truck running. I can get a 1994 F250 4x4 supercab with the 7.5l 460 and a ZF5 speed. I found plenty of threads about the swap from E4OD to the zf5. The main question I have is will my 91 7.5 l be a bolt in plug in and go replacement for the 94's engine? And will it work with the 94's ecm? I know they changed the heads on the 460 in 93 for more power / efficiency . So will a 94 ecm work with a 91 460 ? Thanks to all who read and respond.

 

welcome to FTE.
the main difference between the 91 and 94 is bolt on parts. the alternator is different, so is the belt system. 91 uses "V" belts, 94 is serpentine belt.
as far as the engine swap. yes the 91 will work in the 94. if there is any issues it will be easily fixed by simply swapping the 94 sensor onto the 91 engine.

 

Which sensor?

 

any of them on the engine. there are 4 or 5 different sensors that feed the computer. i have never run into any issues with swapping EFI engines of the same displacement, but i always keep the old engine just in case until the truck is running properly so if i do need to swap a sensor or other bolt on part i have it on hand instead of having to buy it new.

 

Alright thanks. So I also have a 1997 f350 4x4 regular cab with the XL package that has 60,500 original miles on the 460 E4OD drive train. Now I could also swap the manual transmission , t-case and all associated parts out of the 94 into the 91 and then use the interior parts from the 94 to clean up my 97 regular cab as they both have the plain grey interior. The 97 was a maintenance truck for the city of Northglenn Co. So the interior has seen better days. This next question is simply a matter of opinion. I know it is a bit more work to swap transmissions rather than engines but by doing this I can fix / clean up Two trucks increasing the value of my 97. What would you guys do? Engine swap or transmission swap?

 

i think you have a pretty good grasp on the situation!!
put the 5 speed from the 94 into the 91. the transfer case is the same in both trucks, so you will not have to swap that. the only thing you will have to source is a pedal assembly, the 91 and 94 use different pedal assemblies.
then use the better interior parts from the 94 in the 97.
after all is done, you can put the parts not needed on craigs list and recoup some of the build money.

 

Thanks Tjc for all the input. Anyone else have experience with this swap or have links to a swap thread or for all the details? A thread with pictures would definitely be appreciated. Thanks in advance.

 

So when I bought the 1994 I was told that the engine still ran but shouldn't be ran or driven because it was overheating and leaking coolant from the engine. This lead to the previous owner thinking that the head gasket was blown or the head / block was cracked. The serpentine belt was removed and the battery was dead. Also the hoses from air filter box to the coupler connecting to the intake hoses were disconnected. I put a battery in it and cranked it over after adding 8 liters of tap water to the new radiator and it ran fairly good. Still has plenty of power and no ticks or nicks and no CEL while running. Water was leaking out of the driver side front of the engine. Upon further inspection of the leak it is spewing a very fine stream of water / oil from the timing cover gasket right below the bottom of the AC compressor and behind the bracket for the AC compressor and power steering pump and tensioner pully. So good news is it just needs a new timing cover gasket! Since I'll have the timing cover off and the 460 has 156,000 miles should I also do the chain and gear? Or should I just let it be?

 

i would replace it while it is apart.
and closely inspect the timing case cover too. i have seen them rot out and leak behind the water pump letting coolant into the oil.

 

Yes the water pump bolts to the timing cover which then bolts to the engine correct? The gasket that is leaking is the timing cover gasket itself between the cover and block not the water pump. There is water in the oil just hope it's from this gasket not the head gaskets as well. Not too sure how long it was allowed to overheat before it was shut down permanently by the previous owner.

 

yes, that is where i mean. i have seen a few 460 timing covers corrode to the point where they start leaking from the water pump into the timing set and fill up the oil pan with coolant.