That's probably not too far off. My original 170 maxed out at 85 and that was with a good tail wind. A 200 might break 100. Check with 65stanger, he might have taken his up that fast on the L.I.E.
Wow the 6cyl are supposed to be that gutless? When I had mine, it would go about 65-70 on a flat highway, but man it was a TIRED worn out engine I thought that was normal as slow and gutless as it was. It hit 80 one time, downhill. lol
in my 69, with a 200, 3spd stick, pertronix ignitor and flamethrower coil I've done 96 on really bad tires with 3 people in the car. Haven't tried it again since doing a bunch of stuff to it.