I'm going to rip down my 850 holley dp, to check jetting , power valve. i was reading some info. that was on this site last week about PROFORM MAIN BODY for a 850.will this be a good up grade for my holley its said to ad 25-50 hp , but to me that sounds like a sales pitch, i'm putting together a street car ,will this help or hurt me
spend the money or keep it in my pocket :cool:

If you are racing and every tenth of a second is important, then it will be worth your money. It was well worth it for me. If you are planning to do most of your driving on the street; I would save my money, and put it into something oriented towards street performance. An 850 with vac. secondaries would really increase your gas mileage, when compared to your "double pumper". It would still give you good street performance.