my suggestion is convert SG into fully AC and 12581/82 to whatever u want ;)
12581/82 also enjoy the best priority en route at least much better than some high profile 130kmph...sampark kranti is good suggestion but i didn't see any kranti is running on time in NCR..they can speedup by atleast 1hr in both side ...11:10 at MUV is very late as well 12:35 at NDLS..