The chassis in this kit needs a lot of work. First issue is the rocker panels that hang down below the body. I sawed them off and thinned them until they matched the bottom of the body, then re-attached .
Next was getting rid of the spare tire well that wasn't used in 1960. I cut it out, replaced with sheet styrene, then added the ribs to match the other side.
The front wheel sit back to far compared to a 1:1 '60 Chevy, I cut off the the spindles and moved them forward 1/16th of an inch.
These modifications should make for a more accurate chassis.