Modern Vespa

I'm planning an engine build that will require port matching. If I only have a base gasket, will that be enough to provide proper port matching? I haven't ordered my top end yet, but was thinking if I wanted to spread the cost out over time, I could get just the gasket and match it to that. Is that a bad Idea?

would you think it a better use of your time to be able to get it marked out from your correct gasket and then once youve bought the right kit and youve actually got it to port match, you can grind, check and see if it all lines up properly.

Its not really cost your saving here, more like time aye? But it seems a bit of a shortcut.
What if you didnt actually end up buying that kit and opted for another?

My suggestion, just wait till youve got all the right stuff in front of you before doing irreversable operations.

wait till you have the kit
you want to make sure that the kit has enough material to open it up a little since the studs / sealing surface has to be at least 2 mm+

then match the kit to the gasket (metal or paper)

then gasket to case

you can do this in a reverse order from above to make sure that you don't "blow threw" the transfers (mainly the stator side)

go slow

transfers don't need too be that huge to work good
they don't need to be deep and square... sloping is fine
both being the same shape is more important that over all size

have fun