Thanks for the good words, and if we have not allready done so, "WELCOME ABOARD".
I am absolutely sure ALL marine 427 motors got the cross bolted mains, because virtually ALL 427 motors, whether they are in a car, boat, or one of the industrial motors that ended up doing irrigation duty. The 427 was an evolution of FoMoCo's racing program. It began with the solid lifter 390 which was a great engine, competed well in NASCAR, and was a real terror on the street if you could get one. They were rated at 401 hp. Then came the ole 406, essentially a bored out 390, also with solid lifters but at the end of it's very short run, guess what it got? Yes, it got the cross bolted mains. Those are exceedingly rare, as most of the 406 motors didn't get this "race only" feature. Finally the 427 came along, actually 425 cubic inches, bored out to the max allowed by NASCAR and all of them had the cross bolted mains. All of them also had solid lifters EXCEPT in 1968 there was a hydraulic 427 with 390 hp offered in the Cougar XR7 and I suspect a few other models too. Nothing like the ticking of a big solid lifter race dog like that, and running a pair of em is nothing short of a primal scream.
Yes, the surge tank is the closed cooling system, using antifreeze in the block and heat exchangers.
I have a HUGE RESPECT for the MEL series, 430 and 431 plank head motors. Those darn things were run 10 hours before being put in Lincolns, and they were PREMIUM all the way, torque monsters, and could have just as easily been offered as 300 hp motors as they were the 275 selected. There is a LOT of iron in those things, more than the 427. I had a discussion one day with Dan Cook (formally with the CC engine plant, Galipolis, Ohio) about them, and he said those motors were "as good for Chris Craft as any other motor they had" (with regard to customer service, call-backs, etc.) They can undoubtedly be bored out more than a 427, which has thin cylinder walls, being made as light and strong as possible for racing purposes. As a performance design, the 427 wins hands down, but as a long term work hors, the 430 would give anything a run for the money.
But HERE is the ULTIMATE vintage gas V8 of all time, the SEAMASTER 534, which is the largest of the MEL motors, and was used in big ford Super Duty industrial trucks, like fire trucks, tankers, and large construction trucks. At 534 cubic inches, this thing had torque to spare. Man would I love to have a pair of em in my 38. I actually looked at a 38 that had these a few years before I got mine, and I'm sure that boat is still out there. I was afraid of it because it had been used as a dive boat, and I thought it might have been run to long and hard. It would not be an easy task to wear out a pair of 534 Seamasters.