3970014 H 6 9 on back of block
on front pad TO430CNR thanks

1970-73 3970014 350 200 300 2/4
CNR 1970 350 tur hydro trans - 300 4 Caprice/Bel Air/Kingswd

May need to recheck some of your numbers. The block was cast August (H) 6, 1969, so the April 30 assembly doesn't make a lot of sense.

its an H