i changed the fuel filter, maf,tps and oil in my vert when i bought it and it made an insane amount of difference. might help you. the gear thing is possible as well, you probably have 2.73's and he has 3.27's. but 9 seconds to sixty is about as fast an 85 ltd station wagon lol
You said you already checked your Maf, but maybe check it again. I know for the first 8 months or so I had my vert it was horrendously slow, like similar to yours. Then I cleaned the MAf which was very dirty and it felt like it gained 75 horse.