Mike, As far as the switch from the car flexplate to your original 216 flywheel, the initial timing settings for both the original 216 and the 1961 235 are both listed as starting at "5 degrees BTDC". The initial timing mark "ball" and TDC indicator (triangle) on the 216 flywheel can be seen in
this picture from fellow Bolter
Denny Graham. I haven't had much luck finding a pic of an original 1961 flexplates timing marks, so not sure of how to show a comparison to see if the change has affected your actual initial timing starting point or not.
I would 2nd other recommendations on mechanically confirming your TDC position of the rotating assembly and looking to see where the timing marks display in your bell housing window. Posting some pics of what you have, including the flex plate if you still have it, may help to resolve at least that initial timing setting question.
I have no experience with running an electric fuel pump solo or in conjunction with the mechanical pump. Hopefully others will chime in with their info and advice.
