Were all the 351W's Ford blue? My truck, a 1983 F250 4 speed basic 351W 2 barrel registering 140K. My 351W engine is painted red, what does that mean? I have owned it for only a few weeks so I don't know the history.

The truck and motor are in very good condition. The only short coming is that the clutch only has < 25% left (To get it into low gear (granny gear) with out grinding you must press the clutch all the way to the floor hard. Shifting all other gears require normal clutch action.

 

Probably just means the PO painted the engine red after a rebuild.

 

66-80 are ford DARK blue
81-94 are ford gray
95-current are black

 

My '83 351W is dark blue. Totally OEM, too.

 

Removed that hang on A/C today and found that the gaskets on the intake and other smaller ones were not trimmed so my 351W is definitely a rebuild. But, it is a very good engine and I am happy with my purchase (I think). I will let you know more as I get it into shape. It did not run when I first looked at it and now I wish I had not started it before I bought it.

 

This is inacurate. Mostly because I believe there wasn't a specific year that Ford changed the color from Blue to gray in the 80's.

My 1972 390 was Ford Dark Blue. Original Color. Lots of Ford Autolite Parts.

My 1973 302 was Ford Blue, AKA Ford Corporate Blue. Lots of Motorcraft Parts

My 1981 is Ford Blue, AKA Ford Corporate Blue. Always was.

Ford Blue is lighter than Ford Dark Blue, but darker than Ford Light Blue. Some of this confusion I believe comes from the different paint manufacturers and what they call their paint. Rustolium Ford Blue, is Duplicolors Ford Corporate blue etc...

So to say Ford engines were Blue to 1981 is accurate.

Now the really confusing bit...

As for the 1982-1983. Some were Ford Blue, and some were gray. I believe this is because the assymbly plants still had a backstock of blue engines to install, even after the switch to gray.

But there is more evidence to suggest color change...

1977-1982 300-6 engines used distributor cap: D7DZ-12106-A / DH-367
Color of Distributor cap is Ford Blue. Matches engine color. the distributor cap adapter was also Ford Blue, the plug wires were originally Ford Blue etc... All to match the engine color.

1983-1984 300-6 engines used distributor cap E3DZ-12106-A / DH-367-B
Color of the Cap is Gray to match the new engine color. E3DZ-12106-A was updated to E5DZ-12106-A in 1985, Still Ford gray.

That suggests the Engine color changed in 1983 to Ford gray. At least on the 300-6.

With 1982-1983 vehicles, I would look at the Distributor cap adapter, if it is original to the truck. If it's Ford Blue, then that suggests that the engine was originally Ford Blue. If the adapter is gray, then it would suggest that it was gray. Either color cap adapter can be swapped for the other, so it's not definitive proof, but it is evidence to suggest a color prefference.

All I can tell you for 100% certainty for 1982-1983 engines is it should not be red.

 

Unless it is a rebuild. Because my engine is a 351W and it is red. Is there a serial number or block number that would identify what year it is?

 

No red engines built by Ford after 1966. So somebody painted it Red after the fact.

Unfortunately there is no real way to tell what year of engine you have by looking at the casting numbers on the block. I could tell you an approximate year range of say 5 to 7 years, but not narrow it down to a specific year.

The only date stamps Ford used to identify what date an engine was built was by one of the valve cover stickers. Unfortunately, most do not survive after a rebuild. You could look on the left valve cover for any sign of a yellow or white rectangular sticker on your 351W, but I doubt it's still there or legible. Especially since the engine is now Red.