[3 goats]

Originally Posted by ftwmlp

From my research you are correct, WS is the engine code for a TriPower block and the part number will be 9778789 to ensure a '66 block casting. When I went searching for a WS block a few years ago they were not to be had. WT (66 manual trans) blocks were more available so I purchased one of those for a prospective build which has never happened. It is date coded K 24 6.

There is a member here on these forums, Alex S, who from time to time posts for sale some of the more hard to find engines/blocks. You might PM him to see what, if anything, he currently has. There is a commercial yard, Franks Pontiac Parts, that always seem to have some blocks (and much more) available, he is very good about keeping his inventory current on the website www.frankspontiacparts.com. I have not purchased an engine or block from Franks.

Good Luck!

Will do. Thanks!