the use for these is to go from the 454 tbi to what? Am i right??

Pablo, is that what you were talking about when you said they slanted the bores on the adapter plate?

what are the standard carb hole patterns? anyone know this offthe top of their head. are all carb manifolds the same hole patterns?

 

are those adapters?

the bores have to be slanted in some because the carb mating surface isnt wide enough otherwise.

You have three carb bolt patterns (that i know of)

that would be the standard square bore holley type, the spread bore type which is what the rochester Q jets used and alot of spread bore holleys, and finally you have the dominator type which you wont have to worry about cause thats just a huge race peice

if those are adapter part numbers one of them is probably for spread bore manifolds and the other for square bore.