a friend was running the same tyres that you are running & got me to fit them, he told me not to balance them!! Big mistake. I had to go back the following day a balance them which sorted the problem!! One of the front tyres must have been a bad mould coz it was all over the place, took 950 grams to balance so we put as a spare.
Another friend running 35" simex put balance beads in as per the instructions & couldn't hold it on the road @ 60mph! Broke the back beads of tyres & sucked all the beads out (as he was running mechanical front beadlocks which take ages to seperate & refit!!)
Re balanced them using stick on weights & job done all sorted, No vibe's what so ever!!
So might be worth a try getting them done properly???
HTH
Kev