wow- ok, Cheby's fire 18436572, and the dist. turns clockwise. I put # 1 facing #1 cyl. which is if your facing the engine- right side front.
As your facing the engine : 1,3,5,7, are on your right
: 2,4,6,8, are on your left
front to rear as numbered above.

You don't know what cam you are running makes it tough to make any suggestions to help you.
You not knowing the compression ratio same.

Brodix makes a good head for racing & street

Starter carb size formula I use is : cid x max rated rpm devided by 3456 = cfm.
Again, without the cam spec.'s it's going to be tough to use that one. I would only assume that the max rpm would be 7k, but read your plugs after you run it for 20 min.'s at normal useage to check for lean burn.
Good Luck