There is nothing wrong with a 305 engine. I have had several cars that had 305 engines. Check the casting number of your heads, I think it's the 4416 is the good ones. They will have to be ported. F-Bird'88 can give you some good advice of the work they will need. This summit cam would be a good cam to upgrade to. Summit Racing® Camshafts SUM-1103 - SummitRacing.com
. Be sure to buy the kit that includes cam, lifters, and valve springs.