[Formulajones]

I'm guessing from the hints you've provided it's a holley style carb.

Pink cam should be just fine. I find that I use those the most out of the cam kits on many different types of applications, and install it in the #1 hole.

What I'd like to know is what holley style carb specifically, what is the jet spread front to back and what power valve are you using.
I tend to get that part dialed in first before worrying about pump shot.

From there I'd leave the pink cam and start playing with the squirter. Lots of these carbs come with pretty small .025-.028 front squirters that likely won't cover up the big hole you create whacking the throttle on a 455. But getting the front jetting correct, and a power valve that opens at the correct time helping the transition is the first thing to do. Then you might find you don't need to touch the squirter.

You're going to have to open it up and see what's inside for any of us to get you going in the right direction. Backfire through the carb when whacking the throttle is classic lean. Sometimes it's just a big hesitation. If it's doing that when free revving the engine, it's going to do it with a load too.