Has anyone done this? I believe the car shifts to 4th around 135-137 mph. I will be spraying a 200 shot direct port. Im guessing this is not a good idea due to the slow reving load it puts on the motor. Just curious. Thanks

 

Increase the fuel a bit and drop the timing a bit when you shift to fourth and you can do it. Also make sure your cooling system can actually control the temp while on the bottle for that long. systems with thermostats as restrictors will usually have trouble. I'd also run the autolite 472 racing plug for those kind of runs, because you have to keep the plugs from melting.