When I bought my AMC Javelin, it had an SP2P and an Edelbrock 600 on top of the 360. The car ran a best of 15.1 to 14.9 in the quarter at Spokane Raceway. I later switched to a Performer and a Holley 600 (and ok, swapped to 3.15 gears from the 2.87) and picked up almost a full second in the quarter plus gained the ability to bark second gear. I used to have a timeslip in my wallet for my best run of 14.2 @ 99 mph, but it faded away.
(Yes, I realize that's slow. But the car was just my basic daily driver street car.)
SP2P's work better on 318's, Ford 302's, and Chevy 305/307's. Big cubic-inch engines are strangled by them. I'm not kidding! The ports are literally the diameter of a dime! When I swapped from SP2P to Performer, I was shocked at how tiny the ports were on the SP2P.
RamMan ... I’m surprised the SP2P did as well as it did ! It is in no way a HIGH PERFORMANCE intake manifold.
What it’s for is low rpm GRUNT throttle response and better MPG..... and the carb should be tweaked over stick
I’ve even SEEN people making flaming mistakes with the SP2P .... like blocking the heat crossover!
