not sure what shortage y'all speak of..
I occasionally run my narrow search of 73-74 [pre-smog square in californistan] and find lots of prospects..
got a little itch to replace my 74 C20 so I scope it out sometimes for kicks..
https://orangecounty.craigslist.org/...auto_year=1974
straight 73 C20 454/400 for $3650
https://palmsprings.craigslist.org/c...655585173.html
fun looking 73 K10 396 $4500
https://losangeles.craigslist.org/ws...662194779.html
two square running K5's for $16k
https://losangeles.craigslist.org/la...679390391.html
stakes, dumps, 4x4, K5s, etc.. looks like about 10 k5s on there now..
good luck!