In article ,
Steve Kraus wrote:

Anyone with a lot of Briggs experience know if a 390323 carb be used to
replace a 490419 which is NLA? They look identical. Both for 8HP engines.
I suppose there could be hidden differences like the openings in the jet
but I'd think if both are feeding similar HP engines that would be alike
and I can always move the part or get a 490419 carb kit. I'm just really
tempted to solve the issues I've been having by replacing the whole thing.

Did you ever replace all the fuel tubing? A little crack could be giving
you fits.