Inliners International Forums General Discussion Engines Offset Dowel Pins For Cylinder Head Alignment

I'm not sure it's going to help much. The 250 etc. head has its valves in this order:
Exh Int Int Exh Exh Int Int Exh Exh Int Int Exh
The overhang is in the crankshaft axis, but because the intake valves face in opposite directions, motion front to rear will be limited to averaging out the error - not improving all chambers.
To move all of them, the chambers would all have to be alike, such as:
Exh Int Exh Int Exh Int Exh Int Exh Int Exh Int
Like some modern heads (and 12 ports?).
The cross axis (left to right) may benefit from minor tweaking to bring the plugs closer to the bore edge.