I rang up Crow Cams the other day and asked about cams for my 250 powered XA. The engine is stock apart from extractors and a 2 1/4 inch pipe. The guy i spoke to said the cam - part number 63666 would be the best for me. It says increased mid range power with good fuel economy and idle quality. I was told i would get a 15% gain in power. Around how much does it cost to get a new cam put in? I was told i wont need performance springs with this cam. Is 15% a good gain on a pre crossflow 250?