[KobraKarl]

Steve R,

low riser bolts up fine , george Guessford of Guessford machine described the performance of that setup as 41/2 on a scale of ten.

The low rise runners are a bad match with a midrise head ,the bottom of the runner of a low rise manifold is a 1/4" to 3/8"below the bottom of the head intake port making a terrible port match as well as pooling a lot of fuel!,mid rise heads also are about an 1/8" wider than low rise runners.....after i swapped to mid riser the performance difference felt like 50-60 hoarses.

Karl