More carb

[Swede]

Hallo all. I have a 360 in my J20 but the the owner before me has put a 2 barrel Holly on the intake. He says it is a orignal 4 barrel intake so my questien is. Is this squarebore or spreadbore? And wich carb will fits best and be a direkt bolt on to this intake.

[Brown Bear]

Your intake should be a spreadbore. My 84gw 2v intake is. A holly 4v should be a direct bolt on. Edelbrocks are squarebore and would require an adapter.

[jeepbob]

The 4v 360 manifold is considered a spread bore but it is not the same as the standard GM spread bore and the only carb that is a bolt on is a (Ford) Motorcraft 4300 series 4v. While these carbs are ok, they are not the best or the easiest to find. The intake is actually a spread bore with a square bore bolt pattern. To run either a spread bore or square bore carb you will need an adaptor plate. And it has to be one that will seal off the bores (Example, a four hole adapter).

[Swede]

Ok thanks for info. I guess that means I can buy an edelbrock 1405 or holly 600cfm squarebore because I have to made an adapter anyway.