Good way to blow some of the carbon out.
Speaking of: 72 Plymouth Valiant. Trip toKamloops BC from Spokane Wa. There is a fairly steep grade going down the Coulee Dam canyon and I showed my wife how to shift down to low on it. Next trip she made byherself. Yep. Coulee dam to Kamloops some 300 miles in 2nd gear. Tranny rebuild. Luckily not a motor.