Correct carb gasket????

[paulietools]

In my quest and self education to get my truck running right I have noticed what I think to be the wrong carb gasket by the PO. I have an Edelbrock 1406 on an Offy dual port aluminum intake. This is all on my 351. The gasket that was installed under the carb is a standard square bore gasket. The intake manifold doesn't have a square bore opening. It isn't the 4 hole style either. It has what I think is a divided square bore pattern. So my question is: What sort of issues am I dealing with / creating by using a square bore gasket on a divided bore intake. It looks like that the center of the card is not sealed against the intake manifold and that air/fuel mistake can pass under the base the carb into both sets of runners. Edelbrock makes a heat insulator gasket that comes as a divided bore gasket. I am thinking of getting that as I can't find that type of gasket from anyone else. Any thoughts or comments are greatly welcomed.

[gfw1985]

If two of the holes are smaller on the intake you have a spreadbore intake. My son has an Offy Port-O-Sonic spreadbore intake and Holley square bore 1460. Holley tech gave me the right number for the gasket and adapter plate. I'm sure Edelbrock will do the same. Try to find which intake it is from comparing on the Offy website. His is mismatched with high rpm intake and doesn't need that on a Bronco. Best choice would be match the carb with a new Edelbrock intake, but that depends on how much money is available.