I loved the sticky belted tires back in my day. They worked very well for me with 12sec cars, although not like slicks. If the track was indeed prepped right, i'm thinking you need to adjust your launch rpm or maybe you're just dropping more power on it then you think with the cooler conditions these days. :D
P.S. RustyRatRod talking about the rear suspension also got me thinking about the front. You said you have drag shocks, does that included the front? I'm wondering how stiff things are up there also. Thick T-bars? I put 90/10 shock valving on many cars I raced and that definitely helped with the street/treaded tires.
