Unless ya have big lift or turning ya motor to 9k. I wouldn't waste money on them toda under bucket shims. Then you have to pay some one to set them up. If they dont supply the right shims, then they have to grind valve stems.
i just built a motor with them and i think he wasted money on that toda setup when the money could have been better spent else where.
uprated springs for sure. Ya running boost now so boost on the back of the valve is going to counter seat pressure.