rjfurlan,
The link that Hauser provided is probably the most direct and specific information you may find. I was also quite confused, so I posed the "spring" question to Ed at 123IgnitionUSA --- give him a call if you plan on purchasing from him. He was clearly against putting in a longer spring. He sent me a photo of a problem very similar to what Andy (in the link Hauser provided) experienced.
I cannot provide my specific experience as the 123 has only been running for about 2000 miles on the 280. I left the original shorter spring in place based on the information from Ed --- time will tell if I should have gone with a longer spring.
