I think I have a 390 in my 73 F-350 (just bought it) but could be a 360. I checked the VIN and it is a 360 by that, however, the owner said a new engine was put in a few years back and it is a 390.
What numbers should I be looking for on the block?
Tks!
Don
The 360 and 390 blocks are identical externally. The only way of differentiating between the two, since there are no external markings to tell you what you've got, is to measure the stroke. Simply rotate the crankshaft around until the #1 cylinder is at TDC (top dead center) as indicated at the timing mark. Remove the spark plug and insert a wooden dowel into the cylinder until you hit the top of the piston and make a mark on the dowel. (Use the valve cover lip as a constant reference source.) Then remove the spark plug from the #4 cylinder (when #1 is TDC, #4 is BDC) and make another mark on the dowel. Then measure the difference. A 360 has a 3.50" stroke and a 390 has a 3.78" stroke.
FYI: A 360 can easily be converted to a 390 by swapping in the 390 reciprocating assembly (crank, rods & pistons).
352 (4.00" bore / 3.50" stroke) 360 (4.05" bore / 3.50" stroke) - a 352 crank in a 332-390 block. 390 (4.05" bore / 3.78" stroke)Keith
-- FORDification.com The '67-'72 Ford Pickup Resource
One note, all FE blocks say 352 on the front even the 428. :)
Keith and Mark, Thanks for the info! Don
Both of those methods would work too.
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