89 460cid to 1991 7.3l conversion

[rodneyfarris]

i was wondering how hard would it be to convert a 1989 f350 4wd with a 460cid gasser to a 7.3 diesel out of a 1991 f350 minibus. would trans bolt up i have a mazda 5speed trans that has the nonremovable bellhousing. 1991 diesel would not be computerized would it?

[NH2112]

I'm surprised I didn't see this one earlier LOL

The 7.3l didn't share the bellhousing bolt pattern with any of the gassers, so you'll need to get a diesel transmission for it. I'm not sure if your transfer case would bolt to any Ford tranny, or if there were different models.

Ford diesels were computer-free (other than the E4OD computer and RABS module) until the introduction of the 7.3l PowerStroke in 94/95, so if your 460 is carbed all you really need is an ignition-hot source of power to energize the fuel solenoid and glow plug controller. I'd use the oil pressure & coolant temp sending units from the gasser. The diesels have a second coolant temp switch that turns on a light indicating high coolant temp, but most often they indicate a short. Mine's been doing it for well over a year now, I just ignore it. There's also a "BRAKE" warning light that indicates low vacuum, I personally wouldn't bother wiring up anything but a glow plug light.

You'll need the diesel radiator and core support. The radiators are HUGE, cooling system capacity is anywhere from 29 to 31 quarts. NAPA sells a really good aluminum radiator, I'd go with that one if you can't find an OEM in pristine shape. Check the diesel for SCA levels in the coolant with a test strip, if they haven't been maintained be aware that you could be looking at an engine with pinholes in the cylinder walls from cavitation. If the SCA levels are good, be aware that you have to maintain them. Some people install a coolant conditioner filter; I wouldn't because it's not like checking the coolant with a test strip once a year and adding a maintenance dose of SCA is that difficult. Tractor Supply sells coolant with SCA in it, so do NAPA, Navistar, Fleetpride, you name it.

You'll want diesel fuel tanks, since the gasser tanks are galvanized inside and that reacts with diesel. You'll also need the diesel tank senders for the return fittings, but you could always braze some tube into the gasser senders for the return lines.

All in all it's an easy swap, you'll be able to get almost everything you need out of the donor vehicle and shouldn't have to do any fabrication or adaptation. You'll only need to find a 4WD diesel tranny.