I have a 1986 toyota pickup 4 cylinder. I'm looking for some performance gains

[Ashton]

from some aftermarket parts.? Can anyone give any advice on what parts are helpful and give me some links to the information or websites selling these parts. I'm already looking at a k&n air filter to start with. Also what sort of exhaust should I get? I know I need to buy another muffler because the current one has a hole. So maybe a stainless steel muffler with one of those exhaust tips or something. Thanks