JRR you need to have a metal line from the fuel pump to the carb it is a CG requirement. The nipple on the fuel pump is an overflow and should be routed to a fitting on the Flame Arrestor to dump excess fuel into the carb. The manifold is angled to keep the carb level when the boat is running if the carb isn't level the float bowls dont fill correctly and you could have a fuel starvation issue from that. So basically if the carbs are level when the boat is at rest in the water you should be ok look at them and let me know what you think. If they aren't level you can get a wedge spacer to fix the issue and get them level. Why is your motor using so much oil? Do you have any idea how many hours are on them? My 350 Q's have around 1000 hrs on them and use no oil at all. The heads may have a casting number in the valve train area look at my series on rebuilding SBC heads
http://www.network54.com/Forum/424840/message/1139761806
here is a pic of the casting number the last 3 digits are the number of the head in this case 882 heads I would guess you should have 882 heads also. But they may be 624 or something else but they should have 1.50 inch exhaust valves and 1.94 inch intake valves. If you don't you may have an engine that can't breathe right. Regarding the timing marks yes look for a letter on the flywheel next to the "punch" marks or as you said where it looked like someone drilled the flywheel to balance it they are there you need to get a flashlight and look closely. Anything else I can do to help let me know but the part about using oil is really bothering me, where is it going out the exhaust do they smoke excessively? I know this motor backwards and forwards and have rebuilt the top end on one, I had it torn down in less than 4 hours and when all the parts came back it was together and running less than 8.
