rochester carburetor

[79brent]

this is my first post on this forum and i cant find anything else about it on the internet.i just put a new crate motor in my truck and had the carb rebuilt rochester (4m4 i believe) and the vacuum line that goes to the smog pump is capped off but eating my caps because there is gas coming out. is this normal?

[Irish_Alley]

don’t know right off hand but i know you cant use vacuum lines for fuel lines and the lines should be either vacuum lines not both so if fuel is coming out then it would be a fuel line so cap it off with fuel line and a bolt

[bake74]

     1st off welcome to the site.  Like Irish said, vacuum and gas lines in a carb. do not/should not mix.  You said carb. was rebuilt and assuming rebuilt right, it probably is a fuel line. 
      A pic will help us to identify which port you are talking about.

[79brent]

found out the idiots that rebuilt it didnt do it right but it is the vacuum line that goes to the smog pump it just shouldnt have gas coming out haha.well another question what kindanew carb should i get an old rochester or maybe a edelbrock quadrajet? thanks for the welcome

[Engineer]

Many people will call the Quadrajet a "Quadrajunk". In all my years I still haven't figured out why.....

My old '77 Chevy came with a 400sb, and after it blew up I dropped in a 350. That one didn't last either, and to follow it was a 396. All of those engines wore the same Quadrajet carb. I did rebuild it right after buying the truck in 1988, and never had issues with it after that.

If rebuilt properly any pre-emissions Q-jet from before 1978 should work nicely. Although, in order to start in cold weather, the bi-metallic choke coil has to be set up properly. If you can find one of these older Q-jets at a swap meet, you could probably get it for $10.

Also, when I finally pulled that 396, I dropped in a 454. That new engine got a go fast Holley.

[Jason S]

I'm pro-Quadrajet as well. 

Your carb is definitely not operating right, but it could be something very simple to fix (i.e., Gaskets torqued down, float adjustment, etc.).  Before trashing it for a new one, I would go through it and check things out. 

[79brent]

i personally know nothing about carbs but the dude at the shop says its leaking air through the throttle body

[Irish_Alley]

i dont know much about carbs either but as far as i know the quads dont have throttle bodys, but they are known to leak at the throttle butterflys i dont know the proper name for them but its a bushing at the base of the quad

[79brent]

maybe thats what he said. well thanks guys for the help

[Grim 82]

The holes in the carb base plate where the throttle rod goes through can become oblong and will suck air. You can drill the plate out bigger and install bushings in it to true it up. Here is the kit I used.
http://www.cliffshighperformance.com/bushings.html

As far as those lines, there should be no fuel travelling anywhere except from the fuel pump to the carb fuel inlet. Have it rebuilt by somebody that knows what they are doing or do some research and you can most likely do it yourself.