RHS 410 update...

The only time a larger valve is going to work is with porting. I know these come cut for 1.92 valves, but the bowls are large enough to feed the 2.02 valve. And since we blend the valve job, well they work like they should.
A 2.055 intake valve would steepen the short turn too much to help in any way unless you ported it.
I think with a roller cam and porting this could make an honest 530-540HP using the 950HP carb.

Installing a 1" open spacer on a dual plane intake leans the mixture quite a bit. When I bolted the 950 on, it was rich...like low 11's rich! After the spacer it was high 12's which was decent so I didn't touch it.
This was just a quickie dyno session before dis-assembly.