Race car mystery-Help us solve PLEASE

Cudafever said

My vote would be valves spring gone weak.

here is a couple other thoughts. bad axle bearing or maybe in the ring and pinion area.

A rear drum brake adj up to much.

has the car become harder to push lately?

When you look at your ET slip, were does the ET start to fall behind?

Click to expand...

Steve -Cudafever might be onto something here, jack the car up and see if the front tires spin free. You did change the brake set up, try to push the car in straight line and see how easy it rolls. Do have the front end tied down to tight or if the toe or caster is off it will slow the car down.

Check you slip as Cuda said against your old slip when the car went fast
60' times-330' 660' and 1/8 mile and compare them