Holley Help Needed
If I'm right your carb is set up 63 primary and 70 or plate #39 secondary with an 8.5 valve.
If you have to go 4 sizes bigger or smaller you have the wrong carb.
I would try 65 primary jets and plate #11 or 73's in the secondary.
Like others have mentioned you should do the meter block conversion, jets are cheaper.