Ok guys, an update to my carb issues. Regarding the first problem I had with fuel spilling out of the vents, I'm pressure sure it was caused by the fact that I had two power valve gaskets stacked on top of each other. Once I removed one of the gaskets (and used the best looking one), it fixed the fuel spilling out of the vents problem.
But after I get the motor running for a few minutes, it keeps surging until it is warmed up... I know it's an issue with the double pumper as I have a new 600 vacuum secondary carb that I use for testing... two pumps of the pedal and she starts right up and settles down to idle.
A few days ago, I tore the carb apart for inspection again...
I realized I had installed the main body to throtte plate screws in the wrong holes, so I changed that per a picture I found online. Also, my 4150/4160 rebuild kit came with three different gaskets... I lined them all up with the main body holes and picked the closest fit. Once I fixed the correct location of the screws (turns out more than 6 of the holes are threaded) and I changed the gasket, the car would start up and idle better, but not like the vacuum secondary carb...the double pumper still surges for quite a while before it settles to an idle.
Once the car idles, which takes a minute or two of surging and me holding the throttle open a lil bit and goosing it so it won't die, I adjust the float levels, primary first, until fuel just barely trickles out of the sight plugs... I know my floats are adjusted correctly, and the needle and seats are brand new that were included in the rebuild kit (is it possible for the needle and seats to go bad from too much fuel pressure??). As a side note, I was running my Carter mechanical fuel pump with no regulator, and I noticed fuel was actually seeping out of the new gasket between the primary metering block and the main body. Once I installed a 12-803 Holley regulator and set pressure to 5.5 psi, that problem went away, but the surging idle problem still exists... On a side note, when I shut the motor off, I can hear fuel trickling down the intake... but I know for sure the floats are not too high?
**Is it possible I have a bad power valve gasket? I read online that a guy dealt with a bad gasket. The power valve is 100% brand new and I know it's not blown out because I did the Holley recommended trick... tightening the idle mixture screws all the way in the see if the motor dies, which it does.
Anyhow, here are a few random pictures of the gasket scenario I have been messing with, this is the gasket I initially used:
Here are the two other gaskets that came with the kit:
Here is a picture of the bottom of the metering block itself (btw - I made sure to thoroughly clean off all the old gasket material before installing the new gasket):
And a picture of how I finally installed the throttle plate to main body screws:
Sorry for the suuuuuuper long winded post, but I know that with a little help I can have this thing running the way it should.