well you say it has no power and it backfires, if you really want to know how to fix your problem ill tell but first you have to promise to keep this a secret,1 thing you do is go dig a hole. 2. put the 350 in the hole and cover it up 3. go find some old ford "any will do cause they are all potent weapons against GM products" and put it in your ride, and finally youll have a street machine. but remember keep this a secret you promised .