I thought that "TR" on the head was correct for a 69 big block valve cover screw? A guy, who has experience with 69 BB's, says they were R-B-W? Can someone on here definitively clarify which one?
Could it be that both TR & R-B-W were used (mixed) on a 69 BB? This would apply to all 69 Tonawanda BB applications (engine codes & C.U.), I assume?
Would someone please explain when for application/year usage of the "TR" large & small letters? Did small come before large(what I have thought)?