I'm 5 weeks out from my A race—Gulf Coast 70.3

I'm building my run mileage back up and generally feel pretty great. My question deals with race pace work during the long run.

My long run distance is comfortably 7:30/mile. For the past few weeks, I've done a progression during the back half of the run. So, for instance I averaged 7:30/mile for 8 miles & averaged 6:45/mile (shooting for 1:30 run split) on the way back. I had a huge issue with my nutrition in my last 70.3, so I want to make sure my stomach could process food at goal pace.

Is 8 miles @ slightly faster than goal enough? Is it too much?

Wednesdays I do 800s @ 2:50; Fridays' main set is usually 4-5 miles @ 6:30/mile, but if I'm feeling crappy it's just 60 mins Z2. Tue/Thur/Sun are 4mi bricks that are either super easy (8:30/mile) or at a harder 7:00/mile.