Need A Little help Please

I'd hold up on the gears until I checked everything out. In fact I'd wait until after I had the converter right before I changed them............
^^^^This, 100%. With that cam I would want closer to 13:1 compression....just my opinion, but I would definitely not buy gears until you find the lost power...other wise the car will probably just run the same, but in 3rd gear at the stripe.