Total B-body production at Chevrolet was 1,531,714 units. There were 506,153 Sport Coupe bodies made in 1966, and the Impala SS accounted for 119,314 of those cars.
There were another 47,064 Convertibles made that year and some of those could well have been SS models but there was no further break down by model in the convertible.
I can find no break outs by V8 or L6. In 1966 the B-body had two base engines: the 250 cube L6 and the 195 horse 283 2 barrel V8. There were few L6 cars sold (but few still means thousands). The 275 horse 327 was the second most popular motor sold with the 396 and 427 being more expensive optional V8 engines available (the 427 cost less to add to the bottom line cost of the car than did an FM radio).
Just think that Chevrolet was the entry level vehicle (based solely on price) with Pontiac being the "Performance" division and Olds being a few dollars above the Pontiac, but boasting more powerful engines (the Olds Rocket V8 was the first "high compression", high horse V8 engine built starting back in 1963). Then came the dependable Buick and finally the luxury car Cadillac (the division of GM that was started by Henry Ford before he sold it to GM). All sharing the same sheet metal; and differing only in the power train.
That is a bunch of B and some D body cars (the D-body was a B-body Cadillac Limo that had an added 16 inches of room added behind the front seat, but everything else in front of and behind the stretched part of the body was a B-body). So every half cent that GM could cut from a single car added up when you are making over six million units a year of just one body type (not counting the Corvair, Chevy II, or the Chevelle and Corvette while adding the Camaro to the mix starting in 1967, so GM was out producing every other car maker on the planet back then.