I am looking for information on a 4500 series carb. This is going on my 499 motor. Im running them with both with the power valve turned off.
So what I am looking for is what jets to run in this for the first time.

Thank you ................Ted

Check here https://documents.holley.com/techlibrary_carb_numerical_listing.pdf

Sorry, I would start at +8, and then jet for 1330 egt, or lamba stoically. Then, that being safe, would jet for max mph.

Do you know if they are still stock or honked up before you got them
I've used several different stock Holley 1050 CFM Dominators for bracket racing, the original List # 9375 worked really well for a single 4 barrel single plane intake on my bracket 440 motors with stock jetting ( either #91 or #92 (CRS ) front and back ) and no power valves
I'm planning on using them ( I have 3 or 4 of them now ) on my next big HP bracket B1 motor on a fabricated sheet metal tunnel ram intake also

I would also jet up to about a #96 square or #97 and start there...All my 1050's end up there or bigger, but I have not been using an old #9375 Dommy..