Target time/Pacing question!

As the title suggests, I’m struggling with knowing how to pace myself for London in 2 weeks.  Sub 4 hours has always been my target but in January/February I injured my Achilles so didn’t run for 5 weeks so don’t know if that time is realistic anymore. My half marathon PB is 01:52:33 (in November) so sub 4 hours should be achievable but I obviously missed a large chunk of my training. I have only managed 19 miles as my longest run (2:43:43) last weekend and did 15.5 miles yesterday (2:13:03).   I wanted to run with the Runner’s World pacing team on the day but think the 4 hour pace might be a bit quick and should maybe aim for sub 4:10/4:15 but am not sure. What do you guys think??

Your running your long runs way too fast. Your last run was at your half marathon pace.
Even your 19 miler was run at that pace. So where are your marathon pace efforts ?

If you can run 19 at that pace though you should have a decent chance of going sub 4 but it all depends on the last 6 miles or so.

Pace for sub 4 and don't go off too fast.