Engine Carb Issue On 347

Not sure what that smell is. Have you pulled plugs to read what's going on? Do a WOT run and then quickly shut down the engine (after coming to a stop of course) and pull plugs to see what is going on. For carbed vehicles your plugs will tell you pretty much everything you need to know about how your engine is doing.

Have you looked at the butterfly on your carb while while working the throttle to make sure it's opening correctly from idle to WOT.
What is your fuel setup? Pump?
Could have blocked passages/jets, when was the last rebuild or cleaning?

Typically if your carb is too small you won't really slow down after 3/4 throttle you just won't accelerate rapidly anymore is all. It shouldn't feel like a nose dive kind of loss. You have a 347 but you also have small heads so that 600 should perform OK on the street. If your plugs do read lean then you may want to go bigger carb or but bigger main jets is where I'd start.

What cam and intake are you running? Full length headers or shorty?
What is your timing set at?

You could be a little under carbed but I wouldn't do anything till you run your car WOT and immediately read plugs to see what is going on.

Spark plug reading

8 psi is to high. Max for a holley is 7psi. I have found they run best at 3.5 psi. I would check my secondary floats to make sure it is not running empty over 3/4 throttle.
Has the power valve been blocked if so have you went up jets by 10?