These is my thoughts on manifolds, for cobras.
Dual plane for owners that want nothing too radical of a engine, good even power through out the lower & middle rpm range. And, to be able to fit under the hood.
Single plane owners that have pretty stout big motors like mine, that already have high low rpm power, and is going to run higher rpm's and a lot of HP up top. Since I don't plan on making my cobra & motor a race car, road race or drag, I personally, think a overabundance of low rpm TQ, is just plane fun. I'm not so concerned with traction.
If I did race and was concerned about traction, I would build my cobra completely different.
IFS/IRS racing suspension, small block engine, light wheels, track tires, Richmond tranny, ect......
My cobra is for fun on the street, a bit of traveling, and occasional track time.
All out brute force, over the top performance and amazing sounds & feel.
(do you have the cam specs and dyno information on that Shelby FE) ?
Anthony- What are your cam specs & how do you like the solid on the street ?