Hi Chris
Give American Auto Parts in Homebush a ring. They use to sell a twin stromberg kit for greys years ago and had a recommended jet size for the carbs (grey motor carbs). Sorry, I can't find my copy of what sizes to use.
Another alternative is to use the stock manifold, port the throat and re-stud it, to suit a 202 carb. This is what the old Appendix J racers use to do, it works well and is easy to do. Plus with a modified oil bath filter on the carb, it still looks stock.
Hope this helps
Cheers
Tony