For the last 3-4 months, I've averaged in the high 50s/low 60s per week, in singles, with four long runs at 20 miles, one at 21, averaging between 6:45-7-minute pace.
Also, I have a separate 15-miler at 6:19 pace in there.
60 miles a week is not enough for a good marathon.
I have an upcoming marathon. What do you think I'll run?
Not enough information. How long have you been running? Other recent race results? Height/weight?
Assuming you've been running a while and you're generally thin, probably 2:50 - 2:55.
Unless of course you've thrown down a 1:10 half marathon recently, then that might change my prediction downwards.
If you're new to running and "heavier" than a 20 bmi would indicate, you can anticipate a 3:10-3:15.
So, anywhere between a DNS and a DNF :)
Based on all the information given, you are in 2:40 shape. Good luck!