car is 1995 z38 Lt1

am building a 383 lt1 on side wanting to drop new motor right in.
ready to assemble and now realized shortblock was an older lt1, cam has smaller hole opposed to bigger one.

i already have 2nd timing cover for vented opti, no crank pos sensor.
am gonna use electric wp, tc hole already welded close.
i have searched the site and found the specs and what ill have to do as far as dowel pin.

my question is can i have my machinist enlarge the smaller hole, can i buy a vented opti and measure the shaft and then enlarge the cam hole to spec. or what do i do to make this work.

of course getting a new cam would be ideal, but i already got the cam custom cut by isky.

please any help will be appreciated.