So let me start by saying I don't know a whole ton about carbs. I've recently converted my 305 to carbed from TBI to avoid having to reburn the PROM when i add a bunch of stuff (cam, heads, headers etc) call me lazy if you will.

I've just recently got it all together, but when i floor the pedal the carb actually geysers gas out of the primary! I took a peek down in there to see what on earth could be going on (Have a diaphragm style fuel regulator so it couldn't be pressure) and noticed what appeared to be a threaded screw hole puking gas whenever the throttle was played with. Pics below.





The hole that was spouting gas is pretty much dead center of the first image, right above the air horn. Am I missing a piece? Again, pretty novice at this whole carb thing. Going to go to autozone sometime tomorrow and pick up a holley manual, I was just hoping somebody could point me in the right direction.

Oh! It backfired too, when I tried to start it. Bet I blew the power valve.

 

I'm not the most knowledgeable on carbs myself(just swapped the original V6 to a carbed 350 last winter), but you're missing the "squirter" nozzles and hold-down screw. There is a piece that sits there with 2 nozzles in it, one for each barrel and its held down by a screw. When you hit the throttle, its supposed to squirt extra gas down the barrels to compensate for the extra air being pulled in past the opening butterflies.

As for your power valve, there is a way to test it, but I can't remember it off the top of my head right now. I know its listed in a thread here somewhere, try searching "test power valve" or something similiar.

 

yeah, i just spent the last two hours taking my carb apart and cleaning and replacing each piece together crefully. You're missing a screw, a small silver pin and a piece with nozzles like that guy said. I'm sure you can pick all that stuff up at autozone though so have fun.

I even added a pic for ya lol.