Deja Vu - this is the same as a thread elsewhere (another site)what dimensions? you will need some tiny drill bits ( .020-.040") and some solder. it's really not that big of a deal
Dellorto sell a wide range of main jets to suit their carbs, as do many other suppliers - no need to solder and drill.
Buy a couple in the direction you want to go. ie if too rich, buy the next two sizes down, etc, then you can swap and compare and buy another if necessary. They're only about $5 each. Drilling is not very precise and is hard to do properly. Standard drill size increments are very small and very precise. For HT engines with a #79 main jet, #76 makes a big difference and #73 makes an even bigger difference. That's 0.79mm, 0.76mm and 0.73 mm. Can you guys drill to within 0.03mm accurately and smoothly? Easier and better to buy jets. We're in the 21st century now.
...Steve