I have a pair of "spare" 427s that were take outs fromf a 37' Hatteras when it was repowered with diesel. At the time I was surprised to hear Hatteras used the Chris marinized 427, but as stated, it was probably the finest marine motor money could by at the time.
As for oil, I am a big proponent of synthetic oil. I collect, run, and maintain a fleet of vintage specialty cars, including three Porsches and a TVR, I'm also running a pair of Volvos, one of which is a turbo, along with a few other vehicles too. Everything that runs fast and hard has synthetic in it now. My 427 powered 38 has synthetic in the sump now, Mobil-1 15W50 was the choice.
EXTREME CARE must be given to the choice when the oil goes into a solid lifter motor. Tim Toth recently expressed concern for the new fuel efficient oils that use a reduced wear additive intended to prolong the life of a catalytic converter. The new motors are using roller cams and don't need the same level of protection we do.
There are some very good products, and if you look at the oil section of the MASTER INDEX
http://www.network54.com/Forum/503931/thread/1149538484/last-1149538484 you will see some info and my recommendations.
The big danger is this: What you could buy in a can of Mobil-1 15W50 two years ago isn't the same as what is being put into that can today. Also, you can't buy a can of oil that is the same as the spec Chris Craft stipulated when the boat was new (that's an exaggeration, becuase you CAN buy a straight 30W, but it is probably a different chemistry today than it was back then). The point is, you NEED to know WHAT is in that can of oil, and it is IMPOSSIBLE to know by reading the label. That label has milestones the oil must meet, but ten oils put along side one another that all meet those requirements will have a VAST difference in performance. Therefore, we all need to do our homework.
I have not checked the Royal Purple mentioned, but it has a good reputation with racers and I suspect it has a lot of anti wear ingredients. Generally, the racing products are great in a boat because a boat motor has to work hard. The Amsoil Marine/Diesel Heavy Duty is also an attractive product on paper.
I have referenced some test pages that give comparable data on the various oils. This really helps inform the buyer. Beware that things are changing, and don't even think about using one of those new highly marketed fuel efficient 0W30 or 5W30 products.
Regards,
Paul