I've slow a mid ten second car down by advancing the timing beyond 36 degrees up to 38 ( over .10)and slowed it down again by going to 40 degrees We where intentionally trying to slow the car down from mid 10.60 to run S/ST at 10.90, we ended up short shifting the 1st and 2nd gear shift points down to 5500 RPM and reduce the total timing to 30 degrees to get their We tried adjusting the throttle cable to not go to full throttle but went back to full throttle off the line and tried other things to slow it down Over revving the shift points to 7000 RPM in both gears was worth right at .10 reduction also
This was a long time ago,1984, long before throttle stops and the electronic aids available now.