TLDR: installing 1977 seats in 1980 Celica; need to know if it's doable.

So I have an inherited 1980 Celica that had destroyed front seats. Being the idiot I am, I tossed them out and put in aftermarket seat. Wasn't really a great idea as they just sit higher and are a pain to get in and out of. I found a set of seats from a 1977 Celica and picked them up for just over $100. They're currently being reupholstered and I didn't do a test fit (I'll get them in the vehicle one way or another). Need to know how large of an issue this going to be once I get the seats back?