[ihdieselnut]

im looking at a 85 f350, guy tells me it is a 91 7.3, how can i tell diff from 6.9 and a 7.3, it has blade type glow plugs. thanks

 

[Greg77]

He may not have switched the wiring harness over to the late 6.9 7.3 style. Just look at the head bolts, the 6.9's are smaller than the 7.3's.

 

[aceohearts]

The 7.3 uses a 1/2" head bolt, and the 6.9 uses a 7/16" bolt. The heads of the bolts will be smaller on the 6.9.

Also unless he has changed it, the pump drive gear cover will different on the two. The 7.3 has the tube molded into the top of the cover, with a plastic cap, and the 6.9 has the tube as part of the front cover, with a metal cap.

Also the fuel filter housing on a 7.3 has the heater built into it, and the water drain on the bottom of the filter. The 6.9 uses a seperate water seperator.

 

[ltl_jrw]

As for the front gear cover my old 87/6.9 has the same front cover as my 93/7.3 so don't use that.......... Jim

 

[Greg77]

The last years of the 6.9's, 87 and later had bullets on the glow plugs not blades. They also had the same intake manifold and oil fill as the 7.3's, My 87 didn't have a fuel warmer on it either.

 

[ihdieselnut]

boy did i get a steel on this truck it was a 7.3, it has the big head bolts. thanks guys for the help