What are the specs on your current motor??? Honestly i just did the 360 to 408 thing, well mines 412" but anyway if you do it right it is expensive, I have around $6000.00 in mine. maybe thats high?? not sure, but I AM HAPPY with the results, have not had it to the track yet, but seat of the pants from the old 360 to this is incredible, but there is nothing wrong with a correctly built 360 either. Maybe you need bigger cam, etc...