Join Date: May 2001
Location: Chattanooga, TN, USA
of course anything is possible, but the A/C, would make me believe it is not a COPO. (No A/C with any solid lifter car, in 69) It's quite a chore to convert a non-A/C firewall and cowl to an A/C one--especially if the car has not had a frame off restoration.
More likely, it was a big block (X66) and the evaporator was replaced. As the big block evap is not readily available, most auto parts stores, including AC Delco stores, list the same evap for s/b r b/b. Someone probably just replaced the evap core with what was readily available.(You can get a correct reproduction b/b evap core from Old Air Products, in Ft. Worth)
I'll bet the evap box is still big block. look for a bracket, or holes from where one used to be, on the inside half (toward the engine)
The 140 speedo throws me, as it was only available in the COPO1937 "sports car conversion" which include an 11/16 sway bar and 15" rally wheels. To my knowledge, it was not available separately from COPO9560 or 1561(probably why resto4u was thinking COPO) The tach is correct for 325 or 350 horse 396, and A/C was available with either. I'd measure the sway bar. I'd also look for evidence of single fuel line, which would indicate L78 (396/375) or L72 (COPO 427/425) Vapor return line would indicate L35 or L34 (396/325 or 396/350)
Check these things and report back. Then we can continue this "detective work"