Rochester 2GV Question

[oldguy64malibu]

I have a 283 with a Powerglide and with the 2GV carb. The car sat for about 4 years before I bought it. When I took the carb apart for overhaul I found that it only had one of the splash tubes or shields-main well. The shop manual shows two of these tubes. Nobody that I have talked to even knows what these are for or if I can run without the missing one. I do have a problem with a rough idle. Thanks for your help.