I'm trying to find a new or rebuilt tbi for my 89 jimmy. My old one has alot of slop around the butterfly shaft. Can these be rebuilt or is it easier to just get a new one? I put a brand new 350 in it and a new 502-6.holley tbi. But every time I start it after it has set over night, it runs rough for awhile untill it warms up, then it runs fine. I wonder what's making it run rough at start up? Any Ideas to these questions? Thanks.