If it were me, I would go over every bit of my suspension first. I've been 130 in a car, but not even close to 170. Since things change exponentially with increased speed, saying a car is okay at 130 doesn't exactly mean it will be okay at 170.
Look at everything tie rods, control arm bushings, ball joints, tire pressure, everything. There is a very real reason why not every car is able to go that fast, (1) they don't have the mechanics to go that fast/stay stable/stop, or (2) they aren't well enough maintained. I would think that your car fits the bill for the first part, but make sure you're up to snuff on the second. It would really friggin suck to get wobble at 170... I can only imagine the amoung of ground you could cover with just a few degress of error.
What tires are you going to use? Are you having your wheels balanced for higher speeds? Hitting resonence at 160mph would be terrible for your lugs and hubs .
edit: when i say exponential, I mean it. the equation of kenetic energy is 1/2(mass)(velocity)^2 ... you have about 58% more energy at 170mph than at 130.
Last edited by BMWstudent; 05-20-2010 at 01:11 PM.