Weiand Stealth versus Edelbrock performer RPM

A friend of mine wants to trade me me his Weiand Stealth intake for my Performer RPM. Both are new manifolds. I think he wants mine as it is a little shorter for use under his hood. I know both are good manifolds so just wondering what would work the best on my setup. The engine my manifold will be going on is a 521 with D3 heads and a hyd cam and headers not much else. It will be in a F100 short bodied 77 pickup. The cam is one I have had for a long time and when I ordered it I told "Herbet Cams" I wanted the biggest hyd cam I could get that would work with a stock valve train. I think it is slightly more than 500 lift. It worked good in my Fairlane in a 466 before I put the 545 in it. Is it as they say "A horse apiece" or what? 

so now could you tell me why to keep the Edelbrock? I like to learn stuff as I do all my own engine work except the machining. I have an extra old nos 125 hp fixed plate so might put some spray on it for that occasional romp on the highway when Brand X drivers decide to show me how fast their rides are. I know that works. My Y Block went low 12's with 150 hp of spray.