Gentlemen;
Mark is correct. Hence the name;
"steam holes" etc.
Just use the 261" head gasket as
a template and drill into the water
jacket.
-------
The 261 CID engine does have a larger
bore (as posted) but was designed for
'commercial' usage, in large trucks/
Busses. When pulling heavy loads on
hills, the steam would have a place to
escape to (with this improvement)over
the 235", wich was for cars/Lt. trucks.
Good luck.
