I put
BBK long tubes in my 89 by myself in about a day and figured out what not to do. Jack up the entire car as high as you can on stands, the headers will actually go in from the bottom on both sides despite the instructions saying passenger side from top. Put a floor jack under front of oil pan with a piece of 2X4 on it, unbolt the two big engine mount nuts and carefully jack up the engine as high as you can while watching the hoses and wires along the firewall for pinching. Remove old headers, steering shaft, and engine mounts from the block. On the passenger side if you still have the smog hoses remove them also. You need as much room as possible on the sides. As stated above, replace the starter now because you will not get to it with the headers installed. Use a long 2X4 between the block and frame rails along with rolling the floor jack side to side to push the engine to one side as you put each header in. Install driver header first by going up from bottom with the front tip of the primary flange pointed up at about a 45 degree angle between bell housing and bottom of car, you'll figure out the angle and twist once you get under there and try it. Put header on loose with just a couple bolts to hold it and allow engine to move over more. Shove engine toward driver side and do same thing with the passenger header, it will be very tight but doable. Near the passenger side header flange, you may need to slightly grind the corner of the bell housing, my AOD header just barely touches on the edge. Bolt header up loosely with a couple bolts, bolt engine mounts back onto block, center engine with jack and let it back down on mounts. It will take some prying and shaking to get mount pins to sit back in, you must be centered and go straight back down on k-member pads. Finish bolting up headers after remounting engine to prevent tweaking headers. Reinstall steering shaft and smog equipment. The main keys are getting the car high enough off the ground to get the upward angle needed, and jacking engine high enough you can get sufficient side to side movement. Trying to fit headers from top does not work and will be an exercise in frustration. Hope this helps.