i am a massive 138-140lbs in a towering 5'6" frame, i am the only light weight on my judo team, which is made up of mostly heavies, a few things to i have learned is... when Vs a heavy is..
do not let him get grips, at all cost, no grips he can do no throw...
any throw he does land on your stomach NOT YOUR BACK THIS IS NOT BJJ, and or turtle. landing on your back is lossing in judo.
in judo he only has like 5 seconds to force a move. protect your neck and turtle, i hide under my lapel, to block chokes, elbow to knees to block hooks. then they stand us back up. since your a bjj guy i would attemp hip throws if i fail i would fall to my turtle, frocing him to take my back. i would make him work for a tap, and stalemate, forcing us to stand back up. if he is alot bigger he will get more tired going up and down.
certain throws work better on bigger guys than others. my goto throw against a bigger guy than myself is the drop seoinage.
when i go to bjj, and we start form standing. my instructor does eddy bravo sitting start, because he said he does not feel like getting thrown by me. it kinda sucks for me because he is so dominate on the ground, but i think i can get him in judo rules.
"every second your not training, he is..... and he is doing it, just to kick your ass"