Gold Farm Help

Hey friends,

I built a fully functioning gold farm in 1.7.2 a few months ago using the new large portals, water, and hoppers, but since then my hard drive died and I lost the schematic. I've rebuilt it as precise as I can remember, but I'm having issues with my on/off buttons that are rigged up to dispensers with flint&steel/lava buckets, respectively. The F/Steel dispensers seem to trigger 'on' in all 20 large portals except for maybe 2 or 3 most of the time. The Lava buckets are my real issue. I cannot seem to get the clock to function the way it did before. I have the redstone set up to a double pulse for all 20 of it's dispensers (I think), but on about 80% of them, the lava is not sucked back into their respective dispensers (thus breaking/shutting off the portal and eliminating lag). I hope someone can give some insight on my problem, as this has been a head-scratcher on me for several hours. I've only included the top half of the farm because I use the hopper duct mod for collecting on the bottom half, instead of an item elevator. Thank you!!!