[Gaz64]

Ron,

Your 4780 is a 800 DP, has it got four corner idle circuit?

Does the primary metering block have a nipple for vacuum advance on your passenger side?

Are the metering blocks on backwards, primary on secondary side?

I've never heard of a "street carb" without a power valve, my listing for a 4780-4 shows a 6.5 power valve and 31 pump nozzles primary and secondary.

Hope this may help.