Autopar 3000
The Edelbrock LD-340 is a damn good intake, and works so well on the street,
where a little more torque and lower RPM power desired.
Since you already have it, no reason to switch to a Performer to gain at best
nothing.
And, with 8.0 to 8.5 Compression and Small-Valve 360 Cylinder Heads, anything
bigger than a .470" Lift and 270* Camshaft will make that Engine 'flatten out',
especially with a Stock Converter and 3.23 Gears.