Chris- remember that the definition of a swap goes to "engine family" which for a SBC is pretty much everything from the "55 265 up to the introduction of the LS series. Also, port layout is a factor so if by some magic you put the K head on the tractor motor that could no longer run production rules as the port layout is different even though the block is stock. I had same issue running a legal block but with a head that had different port layout than the standard SBC head, therefore not production rules. But, this really is not the point you are trying to make. I understand your confusion and concern.
Displacement of course doesn't enter into it at all.
Not that I have a dog in this fight . . . . .
It seems to me that much of the differences here stem from the definition of what is "production" or perhaps "production parts". Most sanctioning bodies, (not all, I agree), define production parts as those that came "on the car, direct from the manufacturer, including factory options. I'm most familiar with the rules from NASCAR and SCCA which seem arbitrary and restrictive, but:
they make their rules.Some random thoughts from a "wannabe deep thinker" . . . . .A/ Production parts, those produced by the manufacturer, or under license from the manufacturer. So, if you want to race a '28 Dodge, you gotta use a '28 Dodge block and head?
2/ In the aforementioned sanctioning bodies, random "unapproved" blocks, heads, and etc, are not "legal". They get used at the peril of disqualification "if caught". This can really limit what is available.
d/ Freedom of "parts use" has historically and typically been used to "equalize competition", "encourage creativity", or encourage competition entries from less "represented" manufacturers.
1/ Having said all this, I would further add that Gen I SBC are not the same as SB II, although much interchanges. And of course, although SB II stuff has "trickled down" from "professional only use", none of those pieces ever
came in production line autos. What would be the rationale for use in "Production"?
2/ I can only agree that:
a/ An Abarth is not a Fiat
b/ A Gordini is not a Renault
c/ A Cosworth is not a Ford
Although ALL of the above examples are designed using the parent companies dimensions and "packaging", SIGNIFICANT performance differences result from the "aftermarket design".
3/ BMC being the poor, orphan cousin of "real" auto manufacturers, had various "sub-categories" in their engine "family". And the parts DO NOT interchange. Does this open the door to modifications for their use
simply because they are production parts?
I post this simply to foster dialog about what might be a sensible path forward, whether the rules are changed, or remain the same. Changes of this nature need to be well thought out, and discussed, so that they have the "intended result".
Justwonderingboy
