Help - which of these three Q-jet base gaskets is correct for my 72 350?
 

Troubleshooting what may be a vacuum leak and wanted to confirm which of the the following three gaskets is correct for the stock 72 350 SBC in my Blazer with a 17054927 Rochester Q-Jet. NAPA lists one style as correct (bottom right) for the model/engine then lists another style for the carb # (bottom left). There was yet another style I grabbed just in case (top). The carb is a GM replacement for a CA emissions motor.

Thanks!!

Re: Help - which of these three Q-jet base gaskets is correct for my 72 350?
 

Carbs unlimited: http://www.carburetion.com/CarbNumbe...umber=17054927

Go to base gasket at bottom of page.

Re: Help - which of these three Q-jet base gaskets is correct for my 72 350?
 

Top or lower left will work, what does the manifold look like?, what came off?

Re: Help - which of these three Q-jet base gaskets is correct for my 72 350?
 

Are you using a stock dual plane intake???

There's many carb base gaskets. Some open in center, some not.

It can be better to use a base gasket that seperates each side of the intake. This allows better low speed pull on each side of the primary side of the carb. Resulting in better off idle power, AND better MPG...possibly. A Base gasket for a 1984 Chevy pickup (IF I remember...)would fit the bill, IF you wanted to go that direction...

Re: Help - which of these three Q-jet base gaskets is correct for my 72 350?
 

Thanks guys - if this helps it's the stock intake manifold 350 SBC 4-bolt as should be standard in K-series trucks. Well, it's a "CE" stamp block (period GM warranty replacement). I didn't install the current carb (above is that I'm going to install) so not sure what style gasket is currently in place - thinking it's possible that gasket currently in place may be incorrect and a potential leak source.

Re: Help - which of these three Q-jet base gaskets is correct for my 72 350?
 

According to Carbs Unlimited above, its a 4MV carb for a 72 type truck. If it's stock manifold the gasket they recommend is like the one on the bottom left of your pics above.

Re: Help - which of these three Q-jet base gaskets is correct for my 72 350?
 

Thanks - that is the gasket the NAPA rebuild kit calls for, the bottom right is the gasket for the application (72 K10/K5 w 350 4v) per NAPA. I'll go with the bottom left. Thanks for the help guys!