To the OP (Ilmater):
8 miles in 1hr by April 29? Hmmm. You are a big dude. No, you are a HUGE dude which could pose a setback in your goal. What's your age?
If you hadn't attempted distance running once before, I'd be inclined to suggest you find another bet to take. But your 7miles at 1.5hr is a starting point and shows that you could be capable of achieveing your goal if you really put your mind to it. However, how long ago did you run those 7miles? Assuming you ran it yesterday, and you are seriously determined at realizing your goal, then April 29 is sufficient time. But you need to start now, not two months from now. Shaving 30 mins off of your previous time for a 7 mile distance will require extreme dedication on your part, partly due to your physique. And even if you are determined to see this through and end up training regularly, your size may prove to be a bit much for the constant pounding your legs/knees/feet will go through. Which means you may experience some injury related setbacks if you don't listen to your body.
Let me know if you really are serious and willing to see this through, and maybe I can help point you in the right direction. As a reference I'm 31yrs old, 5'11, 122lbs and have been distance running for 7yrs, parrticipating in the Houston Marathon 4 times with a PR of 3hr 6mins. I run 6 days/week at around 50miles/week and train with a group of other serious runners. Finding a group to run with is critical to achieving your goal.