The Overall handling of my 1963 Pontiac Gp has always been pretty good.
I dont go around corners like with my 1987 Corvette Convertible or old 1970 T/A.
Use it straight line Drag Racing on the streets it Really shines excells at because it Hooks up so easy effortlessly from a dead stop on Street Tires 15 x 7 inch wide like a car with 14-16 inch wide Rear Rubber Drag Radial compound tires.
I found the problem Shock on the 63 Pontiac, the Right Rear, lowe rubber bushing swallowed out flattened.
The New 455 engine has so much torque now everywhere found the weak link in the chain.
Car really depends upon the Rear Lateral mounted shocks to control axle rear differential wrap up, much like a typical strong rear anti roll bar does for Solid Axle Drag Cars today.
Lose that lateral link it goes crazy sideways on the gas handling.