273 pilot hole size for T.C.

What year 273? I have a complete '69 273 and it has the large TC register. I believe '68 will also have the large register.

I put a '65 poly 318 steel crank in my '73 340. It had the large register. You have to re-balance the motor though. The poly 318 piston/rod assy are much lighter than the 340 piston/rod assy.

Chuck