slicks for a stick shifter ...

Buschi340 I am running Hoosier 9x26x15 slicks on my dart. I have 60' in the 1.48 to 1.49 on a excellent track prep. but usually goes between 1.50 and 1.54 on a good surface. I tried a set of 9x28x15 M/T but 60' fell off. They were not the stiff sidewall for a stick car and that is probably why.