I would like to know how much power would i get if i change the stock A/C belt for a non A/C belt , and will it be worth it any suggestions

your going to have to buy the a/c eliminator kit to move the power steering pump to where the a/c was, incredibly easy to do i'd say, btw you should post in the 5.0 section from now on

but im saying just changing the belt itself it should give it some power right?

I guess I dont see how it could equal more horsepower. If you want to get rid of the A/C and bypass it you're going to want to buy either the a/c eliminator bracket (which will make it like the stock 1986 5.0 without A/C) or you could buy the A/C eliminator pulley (kinda looks tacky and just a tad more expensive but allows you to use the serpentine belt that your already have). So basically if you want to get rid of the A/C you can get the pulley that goes in it's place or you can get the bracket to move the power steering pump up in its place and a new serpentine belt. You can't just take out the A/C and put a shorter belt on there, makes for some clearance issues doing that.

A/C Eliminator Bracket - $40 (http://www.latemodelrestoration.com/iwwida.pvx?;item?item_no=M8511A50%20%20%20%20%20%2 0%201&comp=LRS )
Non-A/C Serpentine Belt - about $60
A/C Eliminator Pulley - $75 (http://www.latemodelrestoration.com/iwwida.pvx?;item?item_no=ASP-028200%20%20%20%20%201&comp=LRS )

Don't necessarily have to get the ones off of 50Resto but that just gives you an idea.

when air is off the compressor is just an idler pulley gains would be small