when I bought the motor for this truck, I was told it was a 360, then I was told it was a 390 by they guy who built it (my across the street neighbor) worked for the place whom I bought it from, and they said they sold me the motor based on my VIN, and my VIN says it's supposed to be a 360.

I need to know for sure, and I need to know where I can find my engine ID tag to be certain.

Anyone know where to find it, or any 100% certain "Tell Tail" signs of what either motor would have that the other doesn't?

 

Measure the stroke

360 - 3.5 inches
390 - 3.78 inches

 

I have no way to do that at this time, there's been a huge theft streak through my neighborhood, my engine hoist and stand were among the targets, as well as my neighbors.

 

You don't need to pull the engine. Pull a spark plug, slip in a dowel or piece of wire, draw a line on the dowel at the top of the stroke, and again at the bottom. The diff. between the 2 lines will be the stroke.

 

I don't even have a dowel let alone a tape measure.

heh, I'll go grab something I know will work.

 

not trying to jack this thread but i got the same problem (not sure if its a 360 or 390) how do i tell if its at the very top and very bottom of the stroke?

 

Geez, they stole hoists, engine stands, neighbors, tape measures and dowels too?

 

When the dowel is at its highest point, the would be the top of the stroke. When it is at it lowest point, that would be the bottom of the stroke. You are just using the piston to push the dowel up, and gravity or you will have to push it down.

 

I had it all in my snap-on tool box, that was stolen with everything else. I'm amazed how everyone didn't "SEE" anything, it stands as high as I do (I'm the shortest guy in my family) and it's bright red....... I had measuring dowels in there, for this specific reason.

I used a 12" extension, My neighbor was over, got a good kick out of it when I pulled the extension out, glared at it with a smirk "So, what is it" she asked, "It's a boy" i replied, meaning it's a 390, I'm relived, I just bought almost $1300 in parts for it, I'm converting it over to a 4bbl, and some of the parts (and torque specs) don't match up to a 360, now if you didn't know, (at least in my case) it's a serious PITA to return items to Jegs.

 

The timing mark on the harmonic balancer will tell you TDC. When its at that point you have the number one cylinder at top dead center. Pull the plug, make a mark on the rod, bump the motor down until the lowest setting and finally make another mark. Measure the distance between the two marks. Make sure the rod you are using is straight with the stroke of the piston as well.

 

sorry im kinda just learning this stuff... what is the harmonic balancer and how do i bump the motor down to the lowest setting ?

 

No problem at all. Look at the alternator on the left hand side as you are facing the motor. Follow the belt downward and notice it wraps under the round object on the bottom. Thats the harmonic balancer. Now look there as well you will see a metal arrow on the harmonic balancer. On the balancer are numbers when you get close to Top dead center and the TDC mark as well. YOu will probably have to bump the motor over (Do not crank the motor), one, two, three or four or more times gently until you see the marks come up toward the arrow as the number one piston approaches top dead center. Remember you are slowly turning the motor over to make the number one piston get the the highest setting, or top dead center. YOu may have to wipe, or clean off the surface area of the balancer to see it more clearly as well. When you have found top dead center, pull the number one spark plug, which should be the first plug on the left as you are facing the motor, place a rod into the hole where the plug was (angle it with the V shape of the motor as thats the direction that the piston will travel, and make a mark. You will have to very slightly bump the motor and keep checking the distance the piston is going down until it begins to reach the 3 inch mark. At that point gently bump it down, mark it measure, and keep doing that until you reach the 3.5 inches for the 360, and then keep going if it continues down until it reaches the longer stroke for the 390.

By the way, if anyone thinks they are going to find some magic number on the block to identify a 360 or 390, it aint going to happen. It does not exist on these motors. All you will find maybe is a 352 stamp for the block that was used on all the 352, 360, and 390 motors. Dont waste a lot of time searching for something that some egghead said might be there, when it isnt. Measure the stroke and you should know in about 1/2 hour or a little more. Remember to barely bump the motor over when engaging the starter.

I hope this helps.

 

The engine ID tag was originally bolted to the coil bracket. Most are missing by now.

But...considering that so many parts are swapped around, who knows if the tag (if it's still there) is correct for the engine?

The only way to really know what size the engine is...is to measure the stroke.

Ford did not offer the 390 engine with 4WD. 1968/76: The only V8 available was the 360 2V.