square bore / spred bore how to tell

[dazedduster]

I have a 73 340 4bl manifold on my 360, i am tryine to get a carb to fit it
how do i tell if i have a spred bore, square bore or what. i understad its the location of the bores on the carb but which one is what, thanks again for the help

 

[340mopar]

The primaries (front holes in the intake) are small and the secondaries (rear holes in the intake) are large. If it is an original '73 intake it will be a spread bore.


Chuck

 

[fishy68]

Yeah what Chuck said for a spread bore. And a square bore carb like used on the older ones had all the barrells basically the same size.