Square bore or Spread Bore?
Laughing Gas
Joined: Aug 2004
Posts: 964
Likes: 1
From: Roseburg, OR
The Edelbrock is a square bore (I assume you're talking about the Performer). I have no idea why there is spread and square bore out there... well, I've got ideas, but I don't have any good ones 
Moderator
Joined: Dec 2001
Posts: 22,436
Likes: 17
From: Louisville,Ky.
A suare bore carb (Edelberock and most Holleys) have all 4 barrels about the same size. A Spreadbore (Q-jet, Thermoquad, Motorcraft 4350) have small front barrels and large rear barrels. The spreadbore carbs are supposed to have better throttle response and better mileage due to the front barrels being small, but are usually have bogging issues when the rear barrels are opened.
