[GOSFAST]

Just to be clear when changing fasteners, we've never had to align bore/hone from the fastener change only. The ONLY item to check is the clearance between the stud itself and the main cap bolt hole. Occasionally you need to clearance this area slightly. You do not want the stud shank "touching" the holes.

The only fasteners we do not make this recommendation on are the connecting rods bolts, the rods MUST be resized after any bolt changes.

On these "Flattie" mains we've also used the BBC main bolts from time to time. The outer bolts from the Mk-VI (4 B.M.) BB fits perfect with some chamfered ARP washers. (See photo below)

Most Flatheads built here (99%) do get the ARP main stud kit figured in the build.

Thanks, Gary in N.Y.

P.S. We've done a high number of main brg fastener changes and have never found it to create an issue! We've been an ARP dealer since their beginning.