Exhaust temperature differences between sides.

[TAZZ]

1972 318 4bbl. charger automatic. Car ran a little ruff when we got it. Just touch the key and it starts right away. I changed all the plugs, put in a new fuel filter (there was one upstream and one downstream of the fuel pump, and both cruddy), checked the timing, checked for vacuum leaks and made certain the manual choke was fully open. Still running ruff. Didn't check vacuum, I just thought of that. I checked the temp on all the runners on the headers and found all the temps on the passenger side in the +200 degree range while on the driver's side in the upper 300 to 400 degree range. What is that telling me? The heads had been rebuilt not too long before we bought the car. Problem with that head? Perform a leak down test? The previous owner had also changed the carburetor and was told it may be too big for the motor. It's an edelbrock 1905 650cfm. It could be, but I don't think that's the problem. This is new territory for me, and I'm lost. Any and all help would be greatly appreciated.

Edited to add, I just noticed that the fuel "spray" on that side of the carburetor (passenger) is not as much as the driver's side. That my problem, assuming it's a dual plane intake? It's a mopar intake manifold 3671918ae. I will be removing the carburetor to make sure. I also have a good 1406 I'm gonna try.

 

[R413]

This difference would have more to do with the compression, so look at differences in the cylinder heads combustion chamber size, or head gasket thickness. Are the casting numbers the same on wash head?

dual plane intakes are split between the sides so that’s probably not it. The each side of the carb feeds cylinders on both sides of the engine.

 

[MIKESPOLARA]

Fuel distribution differences. Lean runners will run hotter

 

[Lefty71]

I would go for for a compression check anyway. That way you'll learn real quick if there is a problem with your (how recent??) valve job. Sticking exhausts can definitely run up the temps with unburnt fuel.

 

[TAZZ]

The engine ran a little smoother when I put a 1406 on it that we know is good but still wasn't right. I did a compression test as Lefty71 suggested and found that the #6 cylinder had no compression at all. The others were between 115 and 130 except #2, it had 150 lbs.?? Might be a good excuse to put the 360 in it now, I was gonna put in down the road at some point. Thanks for the input guys.