We trimmed the crankshaft counter weights slightly for a few degrees rotation to clear the piston skirts, not the journals as I had written! We could have probably used 6.2 inch long rods, but then the piston pin location would have invaded the rings location with the 9.2" deck height Cleveland block. We were also sensitive to pistons rocking in the bores with too short skirts. This entire build with this combination of components was not the easiest to do! Lot of attention to detail and learned a lot on it! I remember the machinist doing the Mallory work telling me the crank material was tough as hell to machine on the counterweights. I still have this whole engine assembly on the "shelf" today, not assembled!
We started with a real 1972 casting 4 bolt main block, too! Probably getting too old to deal with all this performance in a Pantera, as I bought the car new in March of 1975, and still have it. Had the original engine out and modified with closed chamber heads and forged flat top pistons in late 1975. Engine had the wrong balance flywheel on it. Ford never figured that out, even though they gave me a new short block under warranty as the motor wiped out 2 sets of rear rod bearings and rear set of main bearings in 4000 miles. Darn external balanced motors! Took a balance job during my build to figure that out. Still runs good, even by today's standards once cam, high rise, and Big Throats were added back then on that build. Oh, the memories, and dealing with Ford factory Service Reps back then. Dealer Service/Mechanics weren't sharp enough to figure out the flywheel balance problem either. Re-used it. Even with a new warranty factory shortblock. You would think they would give me a new correct vibration damper and flywheel when they did the new factory shortblock under warranty. On my build, found out the replacement factory short block wasn't a 4 bolt main item. Boy, was I pissed. Too late then!