I have a 1972 chevy truck k20. with power disc/drum brakes. disc front drum back. someone cut my rear brake lines and put water in my brake resevoir. now theres air in all my lines and stuff. how can i get all the air out. i plugged the back brake line and am now bleeding them from the rear. is there any possibilty to getting all the air out or what. how can i go about doing this the best way. and also is it true what i hear about a sbc engine needing backpressure. then how can hot rods and or rat rods run straight headers. is there anything i can do to my carburetor to gain more hp when i run straight header. like change the jetting or something. please all your information is greatly appreciated and needed. engine is a 02 chevy crate engine with a cam and edelbrock 650 cfm carb and edelbrock performer intake manifold. hei ignition by ac delco. and champion spark plugs. and serpentine belt kit. 4 core radiator. o and the truck has no fan and runs 160 degrees all the time.