Yeah, the heater hoses are a real joy! The plugs shouldn't be an issue unless someone did stuff a big block in her.. My 67 with the 390 wasn't fun to change plugs and the worst one was hidden by the master cylinder. So I would pull the valve covers to gain just a bit more room.

I did a vette wiper motor repair once, the one with the vacuum switches to raise the cowl lid... I got so frustrated trying to find the hoses and switches I said the heck with it and pulled the dash and console! I wish I had a camera to get a picture of the owners face when he saw what I had done to his pride and joy!! LOL..