Man i know i've maxed out my speedometer a few times on the highway in 5th gear at 20 pounds of boost on the Z32 transmission with a few hundred RPM to go before the fuel cut off.. (which means i was prob going 120 mph lol.. damn datsun speedo)
I just have a lowered suspension, air dam with a chin, air dam reinforcements and ducting and a BRE spoiler.. felt light but was a hoot =)
Sure the speedo is off.. dunno by how much.. but who cares.. scared the hell outta me.
I remember going to track days where the speedo was just past 135mph.. with a long sweeping left hander braking down to 110 mph or so. a little under-steer.. but i think with a lower and stiffer suspension and some under body work.. it would be stable