That might be true on some engines, but
what determines an interference/non motor
is the Combustion Chamber shape/design
and the valve angles, example, a single cam
2 valve motor like a chevy/ford looses a cam
chain or simply over revved can lunch valves,
a buddy of mine lunched a 302 Ford motor,
he thought he could rev to 9000 RPM, well his
valves springs were double, not tripple like he
thought, and unfortunatly the valves concured,
the only usable parts were 1 head, tricked out
with Chevy 2.02 intake valves, 7 con rods and
the crank, oil pump and cam/timing gear and
misc sheet metal parts.
Block was cracked and one head was junk.
