very nuice wheels fella.
as for the crossover manifold and performance system, all i can say is,
here we go again!!!! ha ha!!
this has been discussed an awful lot here on this forum, and certsin designs have been examined, built and tried.
have a quick search in the 33 section for crossover manifold and you'll find it i'm sure.
the thread died some time ago, or was killed more to the point, but thats political so we shan't go there, but not the overall interest off forum, many folk are still planning variations of exhaust design, including improved manifold layouts, and although the availablity of such items seems scarce, they are in fact still available through a number of routes.
search the thread out and it will all make sense, and should make reasonably interesting reading.
in the meantime, have a look at this.
this is my own 16v cloverleaf with my first layout design, no centre silencers, a slightly straightened final route, and one straight through resonator rear silencer with 2.5" rolled back tip, as per the good old days!
we tested it for volume too because some lads wanted to know wether it would conform to race/track day reg's, which it did.
enjoy the clip, but you'll have to excuse the engine noise, that was my water pump on its absolute last legs!!!!
My Alfa 33 1.7 16V with PetrolHeadParts Crossover and System - YouTube