Thanks for posting the link Kendred... you can find out everything about these rare little Canadian order '71 and '72 Swinger 340 Specials there!!!
As far as engines and engine stampings go, 1969GTS340, could you PM me the full # that's stamped on the block - would love a pic - to verify if it is one of these. The VIN's are sequential on these cars, all built on the same day so I'll know if the number slides into them. Also, the stampings were the last 8 digits/numerals and would look like this 1R267XXX - on the few existing original engines. But, never say never with Ma Mopar - these engines were '70 and early '71 castings, because they were late season builds.
With my website -
www.swinger340specials.ca - I've also built a page that hi-lights the 340 engine thru the years - just an FYI :)-