Quote:

I agree with this Slingshot383

BUT BEFORE YOU DO ANYTHING OTHER THAN MOUNT THEM - PUT TYPICAL AIR PRESSURE IN AND MEASURE CIRCUMFERENCE.

Not yelling - just making an important point.

If the two slicks are not within 1/2" of each other at inflated diameter, take them back.

In addition, and only when slicks are new with no use:
After mounting and setting running pressure, if one has a slightly larger circumference than the other, inflate to 20-30 psi then deflate and reset pressure. Measure again. This can stretch a new tire a little to better match the circumference. If it doesn't change, leave inflated (20-30 psi) for an hour, perhaps in the sun and retest.

1993 Daytona, 5.50 at 130mph (1/8) 1.19 sixty ft (PG). Link to 572 B1 - Part 1