I'm new to mopars, I have a 71 charger with a 400 that's runnin pretty rough has a low end knock and lifters are rattling, I'm thinking about pulling the 400 and putting a 440 in, the 440 is out of a rv so from what I read it has crappy heads. Will the 400 heads fit in the 440? is it worth the effort to swap it or should I just keep and fix the 400

 

You got oil in the pan?

 

Yea just put the pan back on after checking the bearings and a new oil pump becuase I'm getting no oil pressure, nothin to the sending unit, and nothing splashing on top of the motor

 

Is the shaft and pump actually turning?

 

I took the cap off and spun the shaft from the pan and the rotor turned

 

You may have a bad pump.........it happens. You can take it off and spin it with a drill.......check 'er out.........

 

The only time I've had a big block with no oil presser was when the presser relief valve stuck open in the oil pump, broken spring behind the piston.

 

I'm counting on it shouldn't be that it's a brand new high wolume oil punp

 

That can happen too. I've had some low b/c spring was crap.

 

---- If the 440 is decent, low miles etc., I'd go with it. - Improve it over time, and your car will be worth more, come sale time. -- Good luck with whatever you choose.

 

Pull the 400 and combine it with the 440 crank etc. etc. you'll have a whopper stroker motor.