Yeah, buddy ... this one brought Karl out of the closet!! Waa HOO!
Just to expand on what Tim so eloquently explained, we at Stovebolt.com made the conscious decision (egged on by Tom Brownell) to cover all the GM trucks. We choose to end with the '72 model year because after that, they diverge greatly and become more modern. Plus, there are some pretty good web sites out there dealing with the '73 and newer trucks so we didn't feel like we needed to compete with them.
So, according to *our* definition, if it's a truck (or reasonable facsimile thereof) made by GM (or made with predominently GM parts) ... it's a Stovebolt as far as Stovebolt.com is concerned.
Passionate discussions on the subject are welcomed! Encouraged, even. Like Jim "Big Chevy 3600" says, it's all good. Just as long as we stay friends and don't take it too seriously or flame anyone.
To Karl's point, though, if you want to get technical/accurate about it, the true "Stovebolt Six" is the first one -- the 194 -- that came out in '29. After that is debatable.
I call my '72 GMC 9500 a Stovebolt. It has a Detroit 6-71 in it. It's an inline 6 made by GM ... ergo, Stovebolt.

As Tim put it so well, it's the Mindset that matters. We're all here because we all love old trucks and we like other people who do, too. Sortta like Margaritaville ...

So have a beer and let's have a good debate. And when you pass out later, I'll slap some Hello Kitty stickers on yer truck
Hi Karl!
John