intake manifold for 454 which ones best

[NOPHO84K30]

So square bore or spread bore whats the difference I have a square bore performer. I was told it was wrong and should be spread bore ... pros cons anyone

 

[philjafo]

Square bore, spread bore, just refers to the bolt pattern of the carb. Quadrajets are spread bore, the back two holes are farther apart then the front. Holly and edellbrock use square bore, the bolt holes are square. Is one better then the other, depends on if your carb will fit. There are spacers to go from one to the other too.