My research says yes, but nowhere has it been said difinitively that all 1969 SS cars were 12 bolt. Were there any 10 bolts in the 1969 SS??? Thanks.

Yes. All 69SS's came with a 396. All big block cars came with a 12 bolt. The only exception would be a special order 10 bolt, But I don't know if that was even permitted.

Big blocks defaulted to the HD 12 bolt per the engineering parts list. The 10 bolt was too weak for a hi-perf big block.