Let's Make a Deal did have a primetime slot on NBC in the summer of 1967 and beat Ed Sullivan and The FBI head to head. But NBC did not want to become a network of primetime game shows; they had scheduled Hollywood Squares on Friday nights in 1968 (they should have looked at ABC on Saturdays with The Dating Game and The Newlywed Game_. So Monty Hall decided to take his act to ABC and LMAD started airing on Dec. 30, 1968 (daytime) and Feb. 7, 1969 (primetime).
Truth or Consequences was on Channel 4 in 1969; in 1971 Channel 5 was pre-empting reruns of The Lucy Show and The Beverly Hillbillies in the mornimng ad running To Tell The Truth and T or C from 9-10 AM, T or C was on Channel 8 at 6 PM by the fall of 1972; IIRC, Beat the Clock had replaced it by the time of the Channel 8/Channel 2 channel swap.
Truth or Consequences was on Channel 4 in 1969; in 1971 Channel 5 was pre-empting reruns of The Lucy Show and The Beverly Hillbillies in the mornimng ad running To Tell The Truth and T or C from 9-10 AM, T or C was on Channel 8 at 6 PM by the fall of 1972; IIRC, Beat the Clock had replaced it by the time of the Channel 8/Channel 2 channel swap.