I like to swap those early K members to the later 1966 to 1971 B body V8 K members, preferably to the 1968 to 1971 with the better idler arms.
That moves the motors back around 1.5 to 2.0 inches and down a little which helps make the weight distribution better as well as carb air cleaner to hood clearances a little better as well as header choices better