I am running a set of SLP twins on my F7 plus a few other mods and they always run very lean in the mid range. Well after a couple of scuffed pistons I have found the the answer to the problem. I was tolded to use stock F5 needles instead of the stock F7 needles (F5's are richer). SLP specs tell you to run stock needles with the clip in the 4th slot, one step richer than stock. That did not work for me so I tried the F5 needles. Well heres my results, I hope they will help some other people haveing lean issues. I went from seeing 1300*-1400*+ on my digatron in the mid range to 950-1050. This is with the stock F5 needles with the clip lowered one notch just to be safe. The temps outside were about 30-32 so I think I'm going to leave it were its at for now. I might put the stock pilot jet back in just to try and get rid of some of the lowend bog. Hopes this saves some one some $$$.