Hi guys,
I am going to look at a 75 F350 1 ton, and the guy says he was told it has a 390 engine. Some years back, I had several 1 tons, a 74, which I bought new with a 360, a 76 which came with a 360 (later put a 390 in it), etc. Seems I was told at one time that they could be distinguished by the water inlet housing. Don't know. So, I figure there are a lot of you Ford experts on here, and undoubtedly you can tell me what to look for in order to readily determine which engine it is. I will say I was very dissappointed with every 360 I ever had, although the 390 was a good engine. Any help would be greatly appreciated

Thanks

 

Only way to tell is stroke:

360 = 3.50,

390 = 3.784

IIRC a '75 390 in a truck might have been available with a 4bbl.

If it's an original engine you can post the vin or data plate info for a read.

As far as the water inlet housing they are all the same on FE motors.

351m vs. 351w have different water inlet housings, so that might be where that came from.

There was a recent post I'll try to find from another source.

 

I'd count on it being a 360, they somehow all become 390s on sale day since you can't tell any difference by sight. The 360 and 390 are the same block with the 1/4" difference in stroke as posted.


John

 

Pull #1 spark plug out and have a wooden dowl with you about 8" long smll enough to go thru the spark pluh hole and not catch on the sides...Bring #1 up to TDC (Top dead Center) drop the dowl in the hole and mark it at the plug hole.... and I believe #4 at this time is down at BDC...Pull that plug and repeat with the dowl in the spark plug hole (dont rotate the engine) and mark the dowl again....as you did on #1..

3.5" will tell you it has a 360 stroke and 3 3/4" will tell you it has a 390 stroke !!

So many things have been changed by there owners or Mechanics over the years you cant tell by anyone thing from the outside..

~Russ

 

I dont recall 390's ever coming in a 4x4??

~Russ

 

I think I have to agree with the other Russ on this one. I seem to remember Bill saying Ford never installed the 390 into a 4x4. I do got a bad case of CRS though.

 

4x4 F-series in the 70's ONLY got the 360. At least, 73-79, that is, that I know of.

So, if it's a 4x4, and a 75, and it's the original engine, it's definitely not a 390

The only way to tell is to measure the stroke.

 

VERY true - missed that part. It's an F350, so it can't be 4x4. From the factory, anyway.

So it COULD have a 390.

But doesn't really matter.

Measure the stroke

 

Thanks to all of you guys for taking time to reply. And you are right, on sale day, more often than not, somehow the 360 magically turns into a 390! Have no way of knowing if the engine has ever been swapped, although I agree, in 33 years, most likely. Doubt it's original. And yes, it is just a conventional 2wd 1 ton. Wish it was a 4wd, though. I'll take a wooden dowel along and check the stroke, as was outlined. Once again, thanks for everyone's input.

Sincerely,
John

 

Actually, there is more than just one way. If its an automatic, you can pull the transmission flex plate cover, and look at the crankshaft flange. The 360 has a big half moon cut out of the flange. The 390 crank does not. The cutout was necessary to properly machine the 360 crank.

Tim

 

No 390's were ever factory installed in any 4WD.

1965/76 4WD engine availability.

1965/67 = 352 / 240 & 300 I-6

1968/74 = 360 / 240 & 300 I-6

1975/76 = 360 / 300 I-6.
------------------------
There is no way to tell by looking at any FE engine to determine what size it is.

Externally: 1958/64, they all look the same.

Externally: 1965/76, they all look the same.

1958/64's have rounded valve covers with no oil cap holes, and an oil fill pipe.

1965/76's have pent roof shaped valve covers with a hole in each.
----------------------------------------------------------------
The 4th digit of the VIN is the engine code.

1965/76 F100/350

1965: D = 352 2V

1966/67: Y = 352 2V.

1968/73: H = 390 2V / Y = 360 2V

1974/76: H = 390 2V / M = 390 4V / Y = 360 2V

 

here's a how-to ID a 360/390 with pictures!

https://www.ford-trucks.com/forums/9...l#post13616693

 

Hhhm, 2008 thread, won't let me see page 2. Hhhm...