Have a weird suspension problem with my 67 Cutlass. When I start from a standing position then go to WOT it takes off the line fine. Then it shifts into second at around 60MPH(Jetaway) with no issues, but when I get around 70MPH the car feels like it is hydroplaning, VERY scary!! Then when I let of the gas everything feels fine all the way up to 90MPH. Now if I go WOT, again from a total stop to the shift at 60MPH, but this time let off the gas(partially) at 65 there is NO hydroplaning feeling. The ONLY time it seems to happen is if I go with WOT around the 70 MPH point. Doesn't seem to make no sense, I have looked at all the bushings and seem to look fine. Maybe someone here can give me some helpful hints, thanks!!

 

Need a better explanation of the problem, not understanding the hydroplaning description.

 

It's hard to explain...it feels like I am hitting a sheet of ice, almost like the rear end wants to come around or similar to fishtailing. Kind of of scary, but only happens when I am at full throttle. Otherwise fine at even 3/4 throttle, Never in over 50 years of driving have had this issue.

 

I would check tire pressure, upper and lower control arm bolts for a start.