help i think i messed something up -surging under boost

[H W Bush]

i had to replace the idler pulley and i had a temporary pulley in it for a week so i had the blower in and out a few times. well i think something got tweaked because now when i hit 5 or 6 pounds or boost it gives me a powerful surge and won't move past it. also when i'm in 3rd or 4th gear and going about 45 mph and give it at least half throttle, the rpms will go up and then back down. i do not think this is a tube issue. i've checked all the tubes and i had that before and i can go 5k rpm no issue, it's under more throttle the problem is there. i think it might be affecting my mpg too like always.