HR John, thanks for posting fish plate pic's. MY 48 3600 frame was shortened about 10" and I want to put it back...do you have any double fish plate examples? Also how did you get the welds on your '27 to look so good? Did you grind and bondo them? Holy Smoke !
The welds on the ’27 were done using flux core, by an ASME Section IX qualified welder. When it comes to structural welds I tack everything and then have a “real” welder do the welds. Since the guy is a pro the welds were very smooth. After welding the frame was sandblasted and then the body shop handled priming and body filler.
Benny check out this link. It helps to visually explain what Bartamous discussed. There are a lot of ways to skin this cat:
http://67-72chevytrucks.com/vboard/showthread.php?t=123624
