I know the internet is full of these threads, but I'm stuck... I have been working on what I always assumed was a 352 in my 1965 F100. I measured the stroke this evening through the spark plug hole, rotating the engine by hand and am getting roughly 3.25" stroke (all three times i tried, while trying to stay in line with the engine V). This leads me to assume maybe its a 332 with the 3.30" stroke. However, I also have the block casting number of "C6ME-". There's no letter after the dash.

My question is, what do I potentially have? 332? But it seems as though those are early FEs. C6ME would be a 1966 engine, wouldn't it? Is it possible someone put a 332 crank in later FE block? I know the best way to tell is measure bore and stroke but the engine is in the truck, and I really don't want to take it apart just to find out, but plan to do a rebuild in the next couple years so... This has been a great truck and ran well with plenty of torque, but not knowing what I have in it is driving me insane. I've owned the truck for about 7 years, my dad had it for about 5 years before that and I assume he didn't do any work to it so I can't trace back the rebuild... Anyway, any help would be very much appreciated!

 

B&S: 352 = 4.00" x 3.50" / 360 = 4.05" x 3.50" / 390 = 4.05" x 3.78"

No 332's after 1960. Block casting number prefix C6ME reflects 1966, but engine could be a 352, 390, 410 or 428.

Casting numbers are foundry marks, cannot be crossed referenced to Ford part numbers.

 

You will get a more accurate measurement with this method: Rotate the engine to the "zero" mark on the balancer. Remove plugs #5&8 and measure them as you did before. The difference is the stroke. Your 3.5" measurement indicating a 352/360 is probably correct, but it could have 332 internals in it. Stranger things have happened.
Eric.

 

Somebody could have de stroked the motor in the past in an effort to get higher rpm's out of the engine. The best way to find your cylinder volume is to do it the way they do it tech race inspections and fill the cylinders with air in order to get the volume of the cylinder. And then as you noted you measure your stroke with the pencil crayon trick and then work the math equation to figure out what your Bore is