FAT carb

up date,
I took the carb apart, it had a 4.5 power valve in it. I installed what I could find quick a 3.5. Its better, not great. Next thing I will do is open up the secondary plates, they were open a bit and I thought that was a problem and adjusted them closed. It is a 4 corner adjustment carb, I will adjust the secondary plates and readjust the mixture screws, oh and order a 2.5 valve. The rear metering plate has a power valve plug in it.
Next I noticed it had # 78 jets in the primary and secondary metering plates, isn't that a little big for the primary?