Pioneers 3.5's will fit fine as well. They are custom designed to fit the Gm cars of this gen. I mounted mine from bottom just to safe and clear of the dash cover. Just put clips on speaker instead of dash and screw em in. the tweeters on this speaker are pretty flush with the rest of the speaker assembly, whereas others are more raised/elevated causing the fitment issues. I believe they are Pioneer 878's. I have never had a problem with these speakers and installed them in two different cars. Sure there may be better sounding, more expensive options, but I am on budget and was concerned about proper fitment. These have filled the bill!