My guess is that the cam is way too big. Unless everything else on the car is matched up to a huge cam, you've probably killed off the mid-range power so much that the car just can't get moving.

For comparison, take a look at a few of the tech articles on my website. My 505 dyno mule made 800 hp with a cam that was only 266 at 050. Your cam is 280 degrees with a smaller displacement. ( www.arengineering.com is the site, then click on tech articles.)

That cam will work in a super stock type motor with tons of rear gear. Or lots of compression, lots of converter, lots of gear, etc.

Give Dwayne Porter a call and have him spec you a different cam. I bet that if you drop 20 degrees off the duration that combo will pick up a bunch.