'64 LeSabre convertible: http://cgi.ebay.com/ebaymotors/All-Original-2-owner-always-garaged-not-electra-impala_W0QQitemZ220402937349QQcmdZViewItemQQptZUS_Cars_Trucks?hash=item220402937349&_trksid=p4506.c0.m245&_trkparms=72%3A317|65%3A12|39%3A1|240%3A1318
I noticed the different engine as well, but I'm not sure what is in it. I just was the car on e-bay and though it looked interesting.
not a 300, valve cover would sit differnt, it looks like someone switched a 340 into it they came with the 300 aluminum blocks but the 340 would bolt right in with little adaptation if they did so Greg