so, i have a peavey power module - 6 amp fuse - 210 watts - 10-12ohms. running through a 100 watt cab - with a 4ohm - 8ohm switch (unsure what speakers they are - it is modified with an upgrade of speakers) - running through a metal zone boss pedal and an older delay boss pedal. but my frustration is that the heads 6 amp fuse keeps blowing out about 10 minutes into practice i do not know if this is the pedal - or that is is old? suggestions ideas on what to do? scrap the head or upgrade to higher amp fuses?

The fuse keeps blowing because there's another underlying problem. The fuse blows so your whole amp doesn't. Make sure you have the ohms matched up for starters.