Here are my notes from March of 2001 on installing BBK Long Tube Headers
on a 99 Cobra Convertible.
This is the first edition of these notes. Comments welcome. I might eventually edit if I get enough feedback.
1. Disconnect battery negative at battery. 8mm
2. Break loose lug nuts.
3. Raise front end of car and position jack stands just toward the rear of the car on the chassis stubs that are part of the body.
4. Jack stands must clear the front cross member rear bolts.
5. Remove front wheels.
6. Remove steering box bolts which pass through the cross member. 15mm and 18mm.
7. Remove steering shaft bolt 13mm and slide the joint off the steering shaft.
8. Wire up the steering box to the engine to hold it up out of the way.
9. Remove lower chassis brace if car is convertible. (4 or 6 10mm and 15mm head bolts, I think, can't remember.)
These next steps were written around removing the stock cross member for replacement with an aftermarket AJE crossmember. I wanted to leave the steering knuckles, brakes, and front struts in the car.
Note--If the cross member is not to be replaced, it may be easier to remove the lower control arms with the knuckles and springs in place if the springs can be kept compressed with chains, which would be dangerous, but possible. The assembly is very heavy when done this way. I think I read of several people drilling a 3/8" hole in the upper spring perch and bolting a chain there to the sway bar bolt hole to hold the spring compressed. Take this alternative approach at your own risk.
10. Remove bolt at rear of each rear lower control arm bolt so that the bolt can be removed from the cross member. 15mm.
11. Remove sway bar completely. 15mm and 17mm?
12. Place jack under lower control arm and raise up. Install spring compressor on spring, remove lower control arm bolts 15/16 and 24mm. Lower control arm and remove springs. Let lower control arms hang from knuckles.
13. Install engine support in engine bay.
14. Remove motor mount nuts, 21mm both sides.
15. Raise engine slightly with engine support.
16. Place jack under cross member.
17. Match mark the cross member fore and aft and left to right so that it can be reinstalled exactly where it is now.
18. Remove cross member bolts 11/16".
19. Work crossmember down and out. Best to have 2 people.
20. Remove x-pipe and O2 sensors.
21. Loosen EGR tube at EGR valve on intake manifold.
22. Lower engine 2-4 inches. Check for strain at water hoses, wiring harness at front of engine. Do not strain anthing.
23. Remove Starter. 12mm, three bolts.
24. Remove motor mounts from block, both sides. 13, 15mm
25. Loosen large EGR tube nut on driver side manifold. Remove EGR tube.
26. Remove exhaust manifold nuts, both sides, 8 each, 13mm and slide exhaust manifolds off studs.
27. Remove and wipe down stock steel exhaust gaskets. Reuse if needed.
28. Remove dip stick tube retaining nut 8mm and remove dip stick and tube from driver side of engine.
29. Remove lower stud on #7 cylinder and grind off 3/16" on tip to avoid interference with tube. Use antiseize, reinstall stud in head. Check that all the other studs are snug in the head.
30. Install cleaned or new gaskets on cleaned head surface. ( I reused the original gaskets.)
31. Put antiseize on stud threads.
32. Blow out new headers with air from the flange out to the header.
Clean the EGR threads and check for cleanliness. Put
antiseize on EGR connection threads.
33. Work driver side header up into car and on to studs. Hang with two stock nuts but do not tighten yet. Start EGR tube fitting onto header connection and then snug some stud nuts and tighten upper end EGR tube nut. All the header nuts on this side are easy to get to.
34. Work air blown cleaned passenger side header into position on to cleaned surfaces with gasket in place and antiseize on the studs. Start all the nuts and work them down. You may have to lower or rotate the engine to get to the top nuts on the rear two cylinders. Use a stubby 13mm open end wrench. I was able to get to all of them with the engine lowered to the minimum.
35. Reinstall dip stick and dip stick tube--Before installing motor mount. Use a drop of oil on the dip stick tube o-ring and a 12mm wrench to push the tube back down into the block.
36. Reinstall motor mounts and ground wire.
37. Reinstall starter.
38. Raise engine.
39. Reinstall cross member, taking care to match the marks put on before removal.
40. Lower engine and reinstall motor mount nuts. See that engine is not rotated on mounts. Adjust some if needed with engine support.
41. Reinstall steering box and steering shaft joint. Check for tube clearance at steering shaft and #5 cylinder tube. Heat and beat if needed.
42. Reinstall sway bar, if needed.
43. Install O2 sensor extensions. About 18" needed. Use tie wraps to keep wiring harness off of headers.
44. Install newly modified x-pipe to fit long tube headers.
45. Reinstall battery negative.
46. Start up and check for leaks. Let idle for awhile. Shut down, tighten everything one more time. Go drive.
Note--Front end alignment will be affected if the cross member is not installed exactly where it was when removed.
Joe Lynch 12/8/01