Depends on the application & engine build.
Cam size is a big player as well on how it is backed up with a torque converter if applicable, gear ratio and tire size for the drivetrain. The car itself should be light for a single plane.
Here is my blurry dividing line between single and dual plane intake usage. Camshaft duration @050 @ 250*, car weight, 3K w/driver ready to rock, low 11 second range in the 1/4 mile.
If your cam is at the 250* @050, less than 3200 w/a big block looking to to do better than a low 11, then you’ll probably want the single plane.
If your cam is below the 250* @050, more than 3200 w/a big block NOT looking to to do better than a low 11, then you’ll probably want the dual plane.
Being that you have 3.91 gears and not interested in running the track a lot, a dual plane seems to be more fitting. I would suggest a RPM intake. It will offer better low and mid range torque while retaining a good top end.
The cam duration should fit the driving rpm range in cruise. An example would be something like...
65 @ 3000 rpm’s is the cruise speed and rpm.
Have a cam that operates with a minimum starting point below the cruise.
Check the cam grinders min. rpm range the cam likes to operate in. For a mild Hyd cam, this can be in the 240*@050 range. A more aggressive solid cam can change the duration @050 by 4*’s or more. But it becomes much more of a rough idle rowdy cam.
For the above example, 65@3K, a cam that works in the 2500 - 6K range would be fine. Just as an example.
Would also try to get in as much lift as possible to take advantage of the heads flow capability.
