MPG build 360

I should of used the OEM manifold off my uncles 360 That and the 308 heads and msd ignition system oh well . I’m just using what available to me and my local junkyard but I do believe your right about the ignition system. My goal is a high torque at low rpm and that why I went with the 302 heads and the street master or rpm intake. High velocity charge with small intake ports with an over sized piston diameter should be really snappy imo .
now I’m not sure what temp spark plugs I should run in this thing any suggestions?
Also would a carb spacer be beneficial?

29A0B1C0-602F-4249-818D-B61E1356F116.jpeg

9E4B49D2-BB3A-4DDF-B171-B95551981AE2.jpeg