i have built the 4.375 stroke and bore 4.320=513 CID or 4.375stroke and bore 4.310=510CID or 4.375 stroke and bore4.350= 520 CID with a short fill all them can be done with a stock block but would do a short fill on the 100 over with the 4.375 crank with H beam rods there is not much work getting it to swing thru .i have used some of the 4.375 cranks not to big of a deal