I dhave been playing around with my 2258 4cyl (dual weber 44 Idf's). The car drives great. I installed a new 4 channel head temp gauge. I noticed that the 1/2 side of the engine was about 30 degrees cooler. I thought maybe there was simply faulty measurement so I did a bunch of measurements with an ir thermometer. I checked headers case, heads, intakes, tin... and all measurements were about 30 degrees cooler on the 1/2 side. I also looked at all the spark plugs and they all look about the same. The car runs very well however I have a slight pop on decel that goes away if I slightly enrich cyl 2.

Any ideas?

The head temps and header temps are normal on the 3/4 side so 30 degrees low on 1/2 side.

3/4 side naturally runs a little hotter due to air flow under the cooling tins. Assuming you are using stock tins.

Zach

are the flaps blocked on one side I found a piece of paper in tins

I suppose it's possible that there could be a problem with the tin. Why would the headers be cooler also if the problem was just the tins?

The 3/4 side has the oil cooler on it.
That adds more heat to that side, and the cylinders get less airflow.

Should I expect that the headers would also be hotter on the 3/4 side?

Check your intake airflow at 3000 rpm to see if the 1/2 side carb is opening a little less than the 3/4 side carb. If one side of the engine is working harder it will be hotter.

I also read on this forum somewhere while talking about timing:
Supposedly the stock distributor actually retards timing of just cyl #3 because it was known to run the hottest by the designers.

I know of no reason for that or if it is a myth.
I guess someone could check the lobes on the distributor cam.

Supposedly running an aftermarket distributor or a some pertronix modules eliminates the few degrees for cyl #3.

A 25-50* delta between the two banks of cylinders is normal and expected. This is due to the tangential flow of the cooling air as discharged from the fan in a clockwise motion.