I have a 69 gmc with a 350. I pulled the top end off. Cleaned up the heads. New valve seals. Bought and Edelbrock rpm air gap intake and put an Edelbrock 600 cfm carb on it with an accel ignition system. I finally got it to fire up but it will not stay running for more than a few seconds. Ideas?

 

600 cfm is a little small unless you just using it for a daily driver. Is this a mechanical or electric fuel pump? I'd suggest pulling the fuel line off the carb see if the pump is staying up with fuel demand.If you are running an electric pump, I'd strongly urge you to put a fuel regulator on it as the electric pump puts out alot high pressure.

 

It is just a daily driver. Nothing crazy. Just wanted a hair more out of that 350 and wanted it to look a bit more appealing under the hood. It is just a stock(possibly original fuel pump) mechanical needless to say.

 

If the pump is working as it should, possible the carb float isn't set right. Mechanical will run around 10-12 lbs.

 

I’ll see what the pump is putting out. It ran not bad before I pulled it apart. There was one time I drove it and it was backfiring a hunch but other tha that it ran ok

 

'Old school, general rule" with cranking for 5 seconds, you should fill a pop bottle (then 12 oz). Dieing as you posted is lack of fuel, backfiring is ignition

 

I did not know that about the pop bottle. Thanks for the tip

 

So I tried the pop bottle. Counted 5 Mississippi’s and it didn’t even fill half the bottle

 

Well, looks like fuel pump time.