there was a rochester carb on a 56 gmc 270 i bought for the ashton. since i had carb issues on my 51 6100 235 dump truck splash engine. i sent out the carb to get done by a pro with the plans of swapping out the one on the dump. the day came i got it back all happy until i tried to bolt it on and it didnt fit. at one time gmc and chevy as far as i determined was they were the same. chevy changed the stud spacing and gmc did not. at what point they changed i dont know. was the intake on my dump changed i dont know that either without looking at the casting dates. i still have that rebuilt carb sitting on the shelve with no engine to mount it on other than one of my gmc engines which is not correct but will work if i wanted to use it. since i have extra zenith carbs it only makes a good conversation piece.
