[madmaxx]

My SPF came with the Ford Duraspark as all SPF do and then most change to MSD. I have not had time nor the desire to be honest to change mine since my car runs so well. My Ford Duraspark failed at about 20 miles, I went to autozone and picked up a new one for $19.99 with lifetime warranty and plugged it in (about 5 minutes) since then have had zero issues, car runs perfect. I have no doubt the first failure was a case of infant mortality. The Duraspark does not have a rev limiter but I rarely see 5K rpm's anyway. Now I carry a spare duraspark and coil in the trunk (the replacements from SPF) it takes less than 5 minutes to change both, no tools they are both plug and play.

I have to assume the duraspark was used in over a million cars and trucks ford manufactured so the design is proven. Not only that it is $200 cheaper than the MSD and does not buzz like an msd.