I recently modified a HEI out of a 250 Chevy to
use in an 261 Chevy. Should the oil pump drive tang bottom out in the oil pump or should it be raised slightly and then the collar tightened?
Also I read somewhere that an o-ring groove could be machined in the housing and an o-ring
installed to minimize oil leakage. If this is so anyone have any specs for o-ring size and specs for the groove?
One more question--what spark plugs should be used with the installation of the HEI.

Thanks
arnie