I bought a 230/236 cc for a 92 vette engine with the short dowl pin and the small hole on the end of the cam for the non vented opti. I have now decided to go with a vented opti and the ED timing set. Does anyone know the dimensions that I need to open the front hole to. Such as how deep should it be, what circumference and is there any taper.

 

This info came off the board some time ago:

The center hole in late cams is .500X1.0625.

That looks pretty accurate from measurements I have done, myself.

 

Thanks shoebox I had just called comp and they gave me the same info. Your site is great lots of good info.

 

Also comp said there is a 60 degree chamfer on the outer edge of the hole

 

There is a chamfer. 60° sounds reasonable.