How do u think the 95-99 5 speed maximas would benefit from a well tuned sr20det engine and how much trouble do u think it would be to do

 

Sure it would benefit. Cost would probably be about $12,000 or so I'm guessing. After your research you'll want to do a supercharger or turbo instead. Do a search in here and you might find more info.

p.s. these guys here will tear you a new one for asking a question like this before using search.