This had me thinking, a 67 hemi X is worth around $80K, I havent seen many 427 triples for under $100K, obviously depending on condition and their paper trails cars can be worth much more or less, BUT in general terms I would put a "nice" 67 GTX j code car in the $74K to $96K range, a big block tri power vette I would say $95K to 120K, a friend of mine sold his for $140K a couple years ago, I bought and sold mine for $92,500 and it was a super score, today its worth probably $135K...
keep the vette, take that bit of money you would have put into the trade and put it into the vette, not sure what it needs but if its more power you want, that 427 will pick up almost 100hp with some head work, a new cam, a strong spark, and tuned carbs...
I remember a shop that was doing some work for me had a stock "never rebuilt" l88 motor on their dyno, it made just about 580hp!!! Them 427's are no joke, granted that motor is not an l88, but chevy said the l88 was 430hp too, and they were really over 550, lol...
I think the biggest factor (ignoring aesthetics, price, rarity, etc) in driving a hemi b body vs a 427 vette would be the tranny for me, never mind the vette handles 29 times better and you sit in it and feel like you are in a cock pit vs your grand mothers station wagon
, the 833 4 spds are strong as iron BUT shifting manners even i a worked over unit leaves much to be desired, IMO. The vette shifts pretty nice for an old girl..