I was trawling through Wikipedia while eating my porridge this morning
Although originally fitted with an EMD 8-567CR engine of 960 horsepower (720 kW), all were later fitted with 645 type "power packs" (piston & liner assemblies) for parts standardisation, while at the same time keeping their original power output for reliability reasons. Numbers 126-129 were later rebuilt with an EMD 8-645E engine of 1,100 horsepower (820 kW); as used in the 181 Class locomotives.
All but three (121, 125, and 135) were fitted with Train Door Control equipment for operation with the Inchicore-built, BR Mark 3 based, Push-Pull train units. The push-pull equipment of locomotive 132 was subsequently decommissioned. Entering service in 1989, these trains, consisting of a single 121 Class and up to six carriages, were mainly used on the Dublin northern suburban passenger railway service.
Now I know PM is having a sound chip made for these locos and that he is thinking of different chips for the 2 different engine sizes
The EMD 8-645E was also used in the 181's
So I reckon we will have a factory made chip for the 181's when the 121's come on stream
I presume that there would be no reason why they could not be produced before the locos come on stream?
Happy days