do not use the high temp on the motor man, the cases simply will not reach operation temp to final cure it... use a reg powder if not it will be really fragile like paint is... high temp needs to reach high temps to cure and it will simply not do it on your motor... regular powder will hold up just fine (i have coated over 100 set of jugs and never had any issues and we are talking much bigger motors than 350's ... but i have coated 2 sets of 350 jugs)
for the black use SD wet black... it is what we use have him turn the KV down on the gun when he shoots and it will be flawless finish... much stronger powder (normal powder will take 1000 hrs salt blast this will take 3000 hrs) it is what you see i have been useing all ove my bike for the newest rendition of the build
a while back we did a set of sport bike wheels in the sun gold and 40% has a really clean production look to it... will look great
personally i think that metalic black is a bad idea, (even the reg temp powder) a while back we bought over 100lbs and they sent us 10lbs of free powder... one of them was the metalic black. looks like ass man, i have a sample bottle shot of it. if i can remember ill snap a pic, not cool at all.
you want a really cool finish. do that motor in speedway black... with that same 40% gloss over it
the centers of these are done in speedway gloss with full gloss clear... but with the gloss frame and the satin gold the 40% gloss would be best, then you can get a full pound of it... what are you shooting that you only need a 1/2 lb? with what you have listed there for good coverage i would go wiht a pound
Granted we shoot with wagner's so they tend to go though a bit more powder... but i would recomend a full pound of them (except on the jugs of course)
just my 2c man... that metalic black is UGLY!