Will a 76 v8 k-member work on my 66?

I didn't know that you couldn't swap the later K into an early one when I was 16, so I did it. A 69 cuda K member is still in my '66. I did have to spread the rails about 3/4" total. the original was bent on bottom where previoous owner hit a stump. I got a florida airtemp cuda in michigan for 150 bucks!