Engine came with an older B & B and sure looks like a 351 W. Wider up top than a 289/302 series. Casting number above the starter motor is "D1AE-6015-DA 10", which shows it's a 1971 block and I think I've seen some referances to the 6015 number. Inside the valley is Ford's oval and "851 WF10". Coolant comes out horizontally from the Edelbrock Performer intake with "351 W" cast into the top. Bore is 4.040" and stroke is about 3.5" from the slight wear pattern in the cylinder bores. That's 351.8 for the stock bore as it was rebuilt 12K miles ago. Now, the reason I'm concerned is that I'm trying to fit a 427W stroker kit into it. The crank sets right into the main bearings with the old bearings in the place. When I put in a piston & rod(with bearings) and connect it to the crank throw, I measure with a digital caliper that the top of the piston is .100" below the deck. I can almost turn the crank to bring the piston to bottom dead center and the drop measurement is 4.220. There's a bit of interferance between the counter weight and the pistons balance pad, so I figure a little bit of grinding on the counter weight O.D. will probably get me another .050".
Therefore, Stroke should be 4.220" + .050" -.100" = 4.170" as advertised. So,
why is the top of the piston .100" in the hole instead of the .016" according to the specs I've found? Just to get close, I used a 12" ruler and measured from the deck to a dowel in the bearing bore and I get roughly 8 1/8". Add one half the bearing diameter of 3.000" and I get a center height of the block deck of 8.625", where various sources say its 9.5" (9.480" for '69,'70 & '71.) That kinda explains why my piston is down .100". The spec on the con rod is 6.125" bearing-to-bearing center, and the deck height of the pison is 1.280", both of which I've verified with dial calipers. That means the top of the piston at TDC should be 4.170"/2 + 6.125" + 1.280" = 9.490" (a little under the 351W deck height). And one more thing, instructions for engine assembly say that the bottom of each cylinder skirt needs to be notched in order to clear the nut on the con rod, but I'm able to turn the crank (both directions) and bring the piston up to TDC without notching. Has anybody seen anything like this before? I could probably find another rod or flat-top piston to bring compression ratio between 9.5 and 10.0, but what if this is some odd-ball block that wouldn't let aftermarket 351W heads and intake match up?
