I HAVE A 1992 CAMERO RS IT HAD A 305 TBI, NOW IT HAS A 350 4 BOLT MAIN 60 OVER . STILL TBI IT IDLES WITH A LOUP LIKE IT HAS A CAM FROM HELL. ITS A STOCK CAM, REVS FINE I REBUILT THE TBI , PLAYED WITH THE TIMEING , BUT STILL THE CAR ROCKS AT IDLE, MABY SOMEONE HAS HAD THIS . ANY INFO WILL HELP, THANKS.

 

Well if youre using the stock computer that could be an issue.

 

Take a peak at my thread "pulsating idle". Much may apply to you.

Double check for vac leaks at TBI base.

++NOTE+++ not all TBI units use same gasket. some can leak air where the IAC unit resides. the one sent to me with a carb manifold adapter(Howell) would have made a serious leak.