2 different dynos,2 very different numbers.why?

Engine Dyno's are excellent tools - just very easy to manipulate and can vary 10% and more from one shop to another. You have to keep that in mind when relying on Dyno power numbers - and their accuracy - when making an engine purchase. Most of the bigger shops will have a well known reputation for a "Happy" Dyno if their numbers are inflated to the norm. As long as each shop uses the same formula and software when running an engine it can be an excellent tool - even if the numbers are suspect. My criticism is shops that openly advertise these wildly inflated power numbers and get work off of those numbers. As shop owners we all know where our respective dyno reads to the Industry norm so a disclaimer should always be included. IMHO....