Full Throttle Issues

I'm working on my 1976 kz 900 with 29's carbs. My only issue is at full throttle the bike seems to kinda stop pulling, then if I let off the throttle a little it starts pulling again.

I have two areas that I'm looking at first one being the float level and second the petcock. I'm still using the original dual outlet petcock I'm thinking of going to the Pingle hi-flow single outlet petcock.

Am I headed in the correct direction for solving my full throttle issues?

Yes, and maybe the main jets are too small.