Thanks guys for the advise, but I had already read those comments.

Ive been racing for 5 years, and never have issues building my engines, but this was strange.

I did lub the carb with wd40, pushed hard to make it sit properly, but there was no way to make it down enough.

But dont you think I remove to much material, I think it was like 1mm or less, and then it sits down in the block.

The weird thing was both carbs fits perfectly in my 2nd new engine, and both carbs doesnt fit in the 1rst new B5.

There is no big deal (i Guess, lol), because both engines fire it up right away, and no trouble during tank #1.