7.3 navastar

[RalphWD45]

I got took 2 yr's ago on the purchase of a 90 ford 350 superduty flatbed, with a 7.3 navastar, and zf 5spd tranny. My diesel runs good, but pours smoke out behind it, and has poor compression, 200 and change. I found an 86 7.3 bolted to a allison, that is reputed to run well, and no smoke, $900.00 for the pair, or 600 for the motor. Will my fresh rebuilt ZF 5 spd manual bolt on without problems, or will I find that the crank on an automatic is not drilled to take a pilot bearing, simular as to what dodge did with the 318? I don't know diddily about Fords, or diesels!
 

[justanothercase]

From my limited knowledge you should have everything you need. 7.3 is a fleet motor used in many different applications and im not aware of different cranks for auto trans.is this out of a bus? I ask because of the allison behind it. good luck to you.
 

[onefarmer]

A '90 7.3 and a '86 are two different animals. The 86 is indirect injection, has a injector pump and not much if any electronic controls. The 90 is a powerstroke direct injection, no pump, turbo, and the injectors are fired by electric over hydraulics.
 

[GarrettFields]

Onefarmer is on crack. The Powerstroke didnt come out in pickups until 1994.5 You should be fine I used a 7.3 out of a Frito-Lay truck with a allison and put it in my 5 speed 92 F350 that had cavitation issues.
 

[nickg]

An 86 model should be a 6.9 not a 7.3. At least thats what my 86 f-250 diesel is. As for smoking all those 6.9 and naturally asperated 7.3s smoke. Not much difference in a 6.9 and a 7.3. At any rate Im fairly certain it should be drilled for a pilot bushing but Id ask the guy if he would be willing to let you or himself pull them apart to see before you comit to buying it.
 

[onefarmer]

OOOOOPPs I was thinking wrong sorry. You're right the powerstoke didn't come out until 94.5. Must have been a senior moment.
 

[GarrettFields]

It happens! My response didnt come off as light hearted on the computer as it did in my head. Don't want to sound like a pr!ck of misery, you may have the answer to a million $ question I have someday!
 

[RalphWD45]

I want to thank you four guys, that answered me! I have done a lot of motor swapping with gas rigs, but know nothing about the diesel rigs,and my experence has been confined to 1980 and older.I still run a 75 dodge 3/4 ton and 80 ford 1/2 ton, and have had them since they were low miles, used rigs. I need the 90 ford 350, to tow my tractor, hay, hauling trailer, as it is heavier and a duelly, and won't get pushed around by the trailer! THANKS GUYS!