Questions concerning lack of power after 4K

[GRM-REPR]

Do you happen to have a fuel pressure guage before the carb?

No, hadn't installed one yet, not a wild set up. I know I need to purchase one though.

I pulled a plug and it's not WHITE but it's not black, the plugs look normal to me.

In connection to what Wrath is stating about the carb getting enough air, I had thought of that last year. The original shaker hood scoop is matted to the hood, so I don't have the original air cleaner assy that drew fresh air from the outside. I had to cave in and put a Ebrock (heart shaped) filter on. I can't run anything bigger than probably 11''. It's awfully tight under the hood.

Could the problem just be the lack of incomming air to the carb? Thanks for all the responses.