need id help 65 impala ss conv

been saving a 65 ss conv project car for 25 years, got it out yesterday and now im puzzled by vin / body / idplate

vin is 166675s297378

id plate says
08B (august 2nd week ?)
build # 0002350

rear end # DH 702G E (331 eaton posi july 2nd week ?)

car has both upper rear control arms ( big block only?)
car has tricky curvy throttle bellcrank arm (big block)

ok -

when was car made ?
was it 396 or 409 ?

im dying to know ! please help

jack

ive found the info for the vin so far
1=chevy 6=Impala 6=V8 67=2dr Convertable
5=1965 S=St. Louis, MO and the 297378 is a sequential production numbers ill keep looking around and if you can try to get the numbers of the engine

That is amazing my friend and i are restoring a 1965 impala ss convertible also. He has all of the info for it, i'll get ahold of him as soon as i can and find out as much as i can for ya.
Jake