I'm confused and need clarification. Going by the 2007 rule book, I just bought a 322 Buick nailhead to run in XO. The 2007 book says "XO class consists of overhead valve (OHV) and flathead inline, V8 (except Ford and Mercury) and V12 engines, 1959 or earlier design, up to 325 cubic inch displacement." Now the new rule book comes along and reverts to an earlier wording (perhaps the same as SCTA?) with "XO class consists of overhead valve (OHV) and flathead inline and flathead V8 (except Ford and Mercury) and V12 engines, 1959 and earlier design,up to 325 cid." In both books, SBC's are specifically prohibited. I talked with Keith a couple of years ago and he said the intent was to allow vintage non-SBC V8 and inlines a place to run (OHV or otherwise), and that the 2006 rule book wording was in error. I think the 2007 wording was the correction to allow such things as early Olds, Buick, Packard, Studebaker, and other such engines to have a competitive place to run. So my question - which is correct? If I can't run my 1956 Buick in XO, there's no sense in building it. It clearly isn't going to be competitive against a SBC with the superior heads and other technologies available for them.
Thanks
Dan