Hey Jonathan - the Quadrajet carb came from an auto shop near Boston. It had apparently been sitting around for ages in the back of the shop and I just lucked out finding it on Craigslist. If you're looking for a replacement Quad I'd recommend posting a wanted ad over on the forum at Cliff's High Performance (link
). They're super knowledgable and a some of the guys have rebuildable cores for sale. I think all the late 80's 7.4L 4BBL engines used the same 17085212 or 17085004 model quadrajet.
I've uploaded a photo that shows the front driver's area cabinets but it's not the best pic. Let me know if you'd like some close-up shots, measurements, or anything else and I'll grab them for you next time I'm out there.