Power problem after cam and intake swap

[mchyphy]

I recently did a cam and intake swap on my 72 with a pretty much stock 350. I put in a Summit 1102 cam, about .421 lift on the intake and .442 on the exhaust, nothing really radical. The intake I put on is an Edelbrock Performer, again nothing crazy, the intake that was on there before was an Edelbrock Torker II, which didn't really fit the rest of the engine combination. I reused the stock valve springs, which I suspect is my problem. I've got nearly no power after about 2600 rpm. Before the swap it pulled well past 3000 rpm all the way up to 4000. Other things in my combo are mid length headers, true dual exhaust with magnaflows, 600 cfm Edelbrock carb, HEI, a TH350, and 3.08 gears. I just swapped the metering rods in the carb to see if that was the issue, but it didn't help. It pulls pretty well up to 2500 rpm, just falls flat after. Anyone got any ideas? Is it the valve springs like I suspect?