[jonnyk]

He thinks it's too big because....it's too big. You'll have to spin the crap out of a 306 to make use of that cam, and hydraulic rollers don't like going higher than 6500 revs. Keep in mind the street rod probably weights 800-900 pounds LESS than your Mustang, and a bigger cam won't affect it as badly. The Z303 would work much better in a 347.