I have this one, works fine as long as I keep my stock dipstick for actually checking the trans.

http://www.summitracing.com/parts/ati-973081/overview/

67 Barracuda street car, 408, e85, 1.38 60', 6.44 @105.9 in the 1/8 mile, 10.19 @130.5 in the 1/4...so far....