I have one contribution to this thread. My replica is not a Kirkham and my engine is based on a 351W. During my first day of autocross racing, my distributor shaft broke when the
oil pump siezed due to lack of
oil. While the engine was being rebuilt with a better
oil pan, I installed a 3 quart Accusump. With many more days of track time since then, I've never had a problem with low oil pressure. Incidentally, I also put a big red low oil pressure warning light right in front of me on the dash.