the link didnt work for me so I dont know what you saw at autozone,but I got a cherry bomb from az for about $20 .Its kinda loud when I get on it but it made it run better.I dont gear down on hills as quik.dont know where you are but if your not in ca. the cherry bomb is good for the money

oh what a feeling:
#1 86 xtra cab 22R,EB 261 cam ,Hooker header,2" ex with cherry bomb, Aussie powered
#2 86 sr5 4x4 efi parts truck
#3 87 2wd parts truck
84 supra yard art