Need to know about intakes

Hi first time poster,
I just traded for a 86 k30 crew cab daully, It has a genIV 454, w/ edelbrock 750 performer, headers, and a cam that I don't have specs on, She goes through a t400 trans to 38.5 tires, I know I need more Info but, it has the stock intake w/EGR i would love to change that, but don't know how to choose the one I need. I'm hoping to stay with edelbrock. but not sure wether air gap or performer is best. Please help me know what info I need, Sorry for not having much to start with only had the truck for 4 days now.  

Go with the performer as this is a step up from stock plus alot lighter than that cast iron stock one! Unless you know the cam specs this manifold will work. The air-gap will work if the cam is bigger. I asume everything else is stock with the engine. I hope the gears are a little steeper with those big tires, at least 4.10's or 4.56's.  

Thanks, I know the motor has been built up a little, unfortanatly i don't know with what. but i don't want to tear down a good running motor to find out. As for the gears they said they did them, but if they did they didn't go enough, thats my next project. I know it came with 3.73, so if they didn't change them i was thinking of 4.88. and a locker.  

I wouldn't use an air-gap manifold. That particular design eliminates the exhaust heat crossover that is so valuable for cold-starting and economy.

The "Performer RPM" will almost inevitably outperform the regular "Performer" but there is a bit of a price difference.  

Since your wanting to stay with Edelbrock I would just use the Performer.