1985 Supra sunsport 350w not reaching full RPMs or top speed. Power drops off

[Nickgb55]

First off forgive me if I mess up any forum etiquette as this is my first post.

I have a 1985 Sunsport I just bought off the original owner.

It starts up and idles great and has decent acceleration. But just when you get to about 22 mph the power drops off, engine stutters/misfires, RPMs plateau and it can really only cruise at that 22 mph breaking point. If I bury the throttle nothing changes, it just remains at that performance plateau. It almost feels like the throttle cable is not fully opening the throttle.

Boat has:
New plugs/wires (plugs are not gapped just out of box and installed)
- previous plugs where badly carbon fouled all around.
New starter
New ignition coil
New solenoid
New Holley carb

I checked the timing and distributor, it still has the old point distributor but it still functions as it should and is set at 8 degrees at idle.

I think the issue may be in the carb tuning since it was just installed but never tuned. Doing a water test, the secondaries are not opening. I know it is getting enough fuel. We dusted the carb with starter fluid and manually opened the secondaries on the carb but it did not change anything performance wise.

Does this sound like a carb issue to y'all? I have been scouring the forums looking for an answer and I thought for sure it was the distributor but I just checked it with a timing light and it was all good.