do I have a big bore in my motor

[Big Jay]

There is a tool that can measure bore thru the spark plug hole. Don't know the name of it

[woodman]

A friends Bonneville car P&Gd at 350 inches and its 367

[eric_banks32]

If you identify the piston dome/dish, and know the approximate cc of the combustion chamber you can use a burret with appropriate fluid to measure the cc of the cylinder. Make sure the piston is at BDC and the valves are closed. It won't be perfect but it should get you close.

[rapidray]

A friends Bonneville car P&Gd at 350 inches and its 367

See what I mean?!!! Ray.

[headsbikesmopars]

120 lbs on two and 90 lbs on the other two..sounds like it needs to come apart anyway. That is if the valves are all in spec. and no leakage at the head gasket. Then you will know for sure what you have.

Terry