I just got my blazer back from the shop. New tranny, new distributor, and my Holley projection was tuned up. The truck runs great but is sometimes makes a weird noise. I can only describe it as sounding sort of like a dirt bike. Not as loud and it goes away sometimes. Anyone ever heard of this. I can hear it from the engine area, maybe the projection, or something with the exhaust? The sound seems to be just as loud under the driver side. I am not sure what this could be. It doesnt sound horrible but weird. thanks for you help.