FWIW, Pista, I've fit up a 4" crank in a 273 and it'll take some very small bore notches. And yes, the cap bolts for the SCAT I-beam rods (and very probably the Eagles) makes the notches smaller. I am prety much done with that set up except for the valve to bore clearance. The LA-X heads would have been the best for those small bores but now the don't make them. Here is with a SCAT I-beam.