Zathros, thanks for the tip, but your later suggestion is wiser
Boris, if you look for completed ones, you'll see that a lot of t is seen pretty good. But i'll consider your and Zathros suggestion, though no promises
So, I proceeded to the assembly of distribution pipe.
Once again I realized how I do not like pipes and especially bending ones, with addition of paper, which strives to exfoliate at the earliest opportunity.

Extension tubes are not glued, because i don't know if the length will be enough for connection to filters tubes.
I didn't glued the pipe yet, since it was assembled only to help fit carburetors.
Although the black paint has already arrived, I was doubly glad, as I found
black wire with a suitable diameter for pipes from the carburetor to the blocks
and another one for pipes from the radiator to the blocks. So less mess with the paint

In addition, this wire is stronger than solder one.
On the left side, a bar with carburetors is attached to the edge of the block and adjusting the pipes was easy.
On the left side I sweated a little, because the bar is kept in the air on two pipes, and it was necessary to measure a lot and adjust it, so that everything would sit on one level.
As expected - distribution pipe and throttle stem helped to achieve it.