Need help with 64 chevy truck 1 barrel carb problems

Hey Guys, I got the truck running ALOT better. I changed out the carb to intake base gasket. There is a small vent hole on the bottom of carb that leads through the carb to the power piston that opens the power valve. I put a gasket on the base that closed off that hole and now it idles with no choke and will rev up and runs pretty good. I am still getting a hesitation and a backfire through the carb sometimes. I messed with the timing and air/fuel minxture screw and got the same thing. I did find that I think the oil has some gas in it. The oil was and inch above full. It kinda smells like the old dead gas and is very very thin. Do you think the oil/gas maybe getting pulled up through the rings, also fouling out the plugs??? Could this cause a backfire? I feel like im getting some where now. Thanks Guys, Tony  
1964 chevy LB truck 1969 chevelle mailbu

Tony,
If you have been doing alot aof cranking without it firing trying to get it to idle and all that, then the gas in the oil is just a by product of not always firing and it would be good to change the oil before you run in too long. Look for any other possible vacuum leaks and gasket surfaces that might not be perfectly closed up like on the carb to manifold gasket. Does the engine ping under load? I like to turn the timing up till it pings and then back it off till it quits, it should be a little harder for the engine to crank. Now the purpose is to get all out of the engine that you can and to eleminate that back fire, remember that fine tuning is important so listen for the ping(detination is not good for long periods of time) Try running the engine on only fresh gas from a can and see if it runs better and that will indicate the problem is not the carb but the old fuel, and will see if there is a problem with any other part of the fuel system.  

Hey All, I changed the oil and filter the other day and also drained the fuel tank and put in new 89 gas. I changed the carb and put a differant one on and now it idles good and will take the gas. It is still loading up a little as it idles for a while. Does anyone know what base gasket to the intake manifold to use?? The kit came with several. I havent tried driving the truck and listening for spark knock yet. I want to get the bed back on it before I drive it on the road. Thanks Tony  
1964 chevy LB truck 1969 chevelle mailbu

I have a 250 six had fuel filter problems had the rocker arm off value and also had distrilb gear pin break but before it breaks usually runs really ruff.