Stroker402....
Clean out your inbox.
Throw away the catalogs and forget those websites.
Call Russ at Erson and he will set you straight. Or Mike Jones @ Jones Cams. Or the guys at Bullitt Cams. Or even Howard's Cams. Get some professional advice.
I would rebuild the 273, shave the heads a bit for more squeeze, buy the RIGHT cam and drive it.
If you want a 318 I have one you can have.