So I just installed the 351 kit, and my pumper carb is a bit behind so I won’t have it for another week, but I have an event this weekend I’m trying to make it out too. If I run the stock carb, I should be able to get a #130 main jet from my dealer in time, question being will this work for a weekend of some light break in enduro while I wait on my pumper carb to get in? I’m at sea level.

 

I did the opposite where I installed the pumper before the 351. The jetting from Bill was perfectly usable on my bike. I did not see much change after installing the 351, still very close jetting and perfectly usable.
Every bike and setup is different, but I would run it and see.