Class 31 hauled trains on Great Eastern
 

Does anybody know whether pairs of 31/4s worked out of Liverpool St to Norwich?

Also, did pairs of 31/4s work via Cambridge to Norwich?

I do not think that double headed class 31/4's would of been used on the Liverpool Street Norwich tains on a regular basis. By the time the conversions were done the top link trains out of liverpool Street would of been in the hands of the class 47's. I understand that the 31/4 were very underpowered anyway, so they would of not been very popular on Inter-City services.
31's did work regular duties between Norwich, and Birmingham. However these trains were normaly handled by a single loco. These may well have been an ETH fitted example in the days of the provinval sector. I can not rember if these trains ran via Cambridge which would of needed a run round there. I understand there was even a 31 hauled train from Stansted airpot to Birmingham. Again a single loco used.

I've lived alongside the Liverpool Street Norwich line for many a year and dont ever recall seeing a double-headed Brush type 2 hauling carriages on that route.
I do recall seeing single locos pulling the Birmingham Norwich trains through March (another old haunt). Double-headed locos were something of a rarity in the Eastern region as there was never anything that heavy and the hills can be counted on one hand.

I remember getting 31 haulage between Birmingham & Leicester on the Norwich service many times in the late 70's although these were always mk 1 corridor stock so would be steam heat 31/0 or 31/1 types

I have some photo's of these passing through March (now a Regular haunt for me these days) and will have to look them up.