Thread: Ford FE Big block identification

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i have a ford fe ribbed big block in my truck right now and i cant find out what the ci is. its the side oiler and where the casting number is it says a line with balls c 5. im pretty sure that would mean 1965. the heads are 1968 with 2" I and 1.5" E valves. the right side top of block above lifters says 27 which id hope means 427. the pistons are a 4" bore and i just want to know if anyone would know what exactly the engine is.

Unfortunately Ford FE casting numbers can leave a little bit to be desired as far actually being able to identify what engine you have.

Then there is the interchangeability of FE piston/rod/crankshafts which will let you come up with a varity of displacements. A 352 has a bore size of exactly 4.00 inches, while the 360, 390 and 410 have a bore size of 4.050 inches. It is not uncommon to find 352s that sometime in their life have been bored .050 (to standard 390 bore size) and turned into a 390 with the use of 390 crank rods and pistons, and the same holds true for 360 being converted to 390s.

The only real way to tell what you have it to accurately measure bore AND stroke. You aren’t going get the accurate measurement you need (down to the thousands) with a tape measure. You need to remove the carbon ridge at the top of the cylinder to get you’re measurement and also clean to top of the piston to determine if it has been overbored ( oversize pistons generally have the oversize stamped into their tops). The you need to get a good measurement on the stroke. Once you have that it fairly simple to run the numbers thru an online calculator to determine what you have.

On a side note, if it has an exact 4.00 bore it’s probably a 352 and a 4.050 bore is likely a 360/390.