Hiya Kermit. FYI there is still a chunk of your boat bracket here if you need a desk paperweight.

Best I don't know, but the most fun engine I had was a thin flange early 1275 block.  Stock 1275 crank.  Modified S rods with SPS Unbrako bolts, bolt heads ground to a taper. Flathead pistons +.020", Total Seal rings.  4130 4-bolt center main cap.  Boffo 460 cam.  Longman inclined valve head, even though that reduced the rocker ratio. LCB exhaust, straight pipe exiting just at the front of the rear sub.  45 Weber on a 5.5" manifold.  Reed valve on the breather can.  That baby would singggggg...

My best fun engine was a stock 1100 lower unit we used in our RallyCross car, we had blown up both 1500 injected 8 ports so as we'd paid the entrance fee we fitted a knackered 1100 lower and fitted the longman head and splits from an old 1380 did'nt adjust jets or anything just went out and revved the S***e out of it didnt go anywhere but what a fun weekend no pressure and just a barrel of laugh's

The best engine we have ever had was in 'ol 35' it had every thing wrong, small port longman head, small headers, goose neck manifold, std rockers, 648 cam. Kicked butt.  Everything worked together.  Think about it ...