Trying to get the most out of a 22RE

Hey guys so I sold my old truck (1991 Toyota Pickup) to my very good friend and he was really wanting to know how to get the most out of the 22RE that sits in it. Its an amazing truck with a bullet proof motor but,as you know, there can always be more to accomplish. I didn't really know what to say to him but I figured there are so many Toyota experts on here you might have a few ideas that i could pass on to him.
Can I get your help?

 

engnbldr is popular for heads and camshafts. You can build your own performance kit with them. Combined with a good header and exhaust it will wake up.

 

i know my friend has new headers/exhaust system along with a new air intake. hes is wondering if there is any type of machine work he can do to his engine to get more out of it.