Greddy's kit has 6whp more than the Blitz one, and also if you compare price of the two Greddy's is cheaper in most places that sell both kits. Reliability just depends on what you do to upgrade internals, tranny, and other parts that could wear out fast. Both are reliable kits.quadoptix said:actually ive ran against both..the blitz seems to run better compared to the greddy.