I like the caps w/ the brass contacts. In my experience they seem to conduct current better, making the car run better.
One of those "fuzzy feel goods"... All else equal, type of conducting material makes no difference in a new cap... The aluminum caps do tend to deteriorate more quickly, especially in a Hi Energy ign system... OEM's switched to Aluminum caps in the '60s as they were cheaper and by time they failed, tuneup was recommended anyway...
So conclusion (hopefully), I've ordered and am still waiting for my valve cover gasket for that oil leak, I have changed spark plugs, cables, distributor cap and rotor, put my nose in the carb, it was not too lean but way too rich! That might have been going on as I had a minor vacuum leak that got bigger (and made me notice it and mistake it for an exhaust one) that was a split line and a rotten plug. Changed those and checked the rest hopefully it was all. Also changing the motor mounts was not enough as my trans mount was also falling appart but didn't even noticed it until I fixed vacuum, carb and distrib and a weird vibration was still very present... All that taken care of and it seams now everything runs smoothly. Until next thing of course. I still have to get its alignement redone but that will happen soon So thanks you all!!!