i had a 304 jeep engine pro built one time(edelbrockcam,lifters,timingchainset,performer intake milled heads,etc)and the shop said they would warranty the motor if they installed it and assembled it,so i said ok.i go to pick it up and won't rev over 2k and raw gas is coming out of the tailpipes.they tell me my 600 holley is just way too big.to make a long story short i tore the motor apart to find the cam off 3 teeth,i installed it right and it ran great so yes even 1 or 2 teetf off will make a difference.