what mods could i do that would make a 4oo rip...possibly big bore and what not, but without the pain of rejetting and having those hard to find jets?
i am on a budjet of around $1,000...actually no more than $1,000....so what could i do to make my 400 rip?

 

No way around a rejet. Anything you do to the intake or exhaust will require a rejet. Learn it early in life.

First is Change the exhaust - your favotire one- slip on unless you plan on getting a Big Bore
Take off airbox lid - if you only run in dry areas
K&N air filter or a UNI - Get outer wear
Jets - various sizes
That's about it and should only be about $400.00

After that change Cams and do a littel porting on the head and you'll be fine. Don't waste money on a Rev box until you change the cams that need the higher RPM.