PL42s. Success or failure?

The GPs are exempt from tier 4 regulations due to their age. Based on the contract that was awarded last summer (IFB No. 21-032), "This project involves the overhaul of four (4) EMD 16 – 645 E3B model diesel locomotive engines to include upgrading these engines to meet US Environmental Protection Agency (EPA) Tier 0 locomotive emissions standards as required by 40 CFR 1033, which also requires that the locomotive they will be reinstalled into will need to be equipped with an Automatic Engine Start Stop (AESS) system".

Are the GP40s proposed for overhaul from the CNJ (4100) or PC (4200) series?

bid says "work engines" which presumably means non-revenue? 4300 series?