I had a 87 Chevy Camaro an I had to change the in tank pump 3 times. It is a Bi*** to do. As for cutting holes I would avoid that route I saw in a old Hot Rod mag a fuel pump swap out kit I will try to find who made it an if its still made. It replaces the in tank pump with a frame mount pump. I curently owna 90 camaro an at least the filler neck on the 90 comes off the tank The biggest problem with the pre 90s is the damn neck an how the tank comes out. U will learn many new words when doing this job.
Dark Man