Depends on where the leak is. Is it the manifold to head area? Is is a broken manifold bolt? Is it the manifold to exhaust pipe? I have read some of the stock manifolds develop cracks.
A leak could be several areas with very different fixes. Also the 460 manifolds I think used to have usual manifold to exhaust flanges with a gasket. Later models have a cone and cup design which in my opinion is prone to leaking due to heat(like towing) softening the pipe and allowing the cone to shift.
If it is a manifold to head leak, then removing the manifold and cleaning the area and using a new gasket is a good idea. Be SURE to use some sort of penetrant on the bolts. If the manifold has been in place for awhile the bolts may be rusted all to heck and you have a good chance of breaking some, and then you have a real PITA.
I would bet someone makes headers for just your swap. If it was me, I would probably go with a good set of headers. But then you are probably not suffering from any lack of power as it is so if your stock manifold is in good condition, it may be just easier to keep it.
It is leaking from manifold to head, and yes the bolts are rusted badly. I am interested in using long tube headers if possible. I have plenty of HP had it dynod pushing a little over 500 HP. Headers would make a little difference though.
Yeah, was afraid of the rusty bolts. Best bet is to spray the bolts with a penetrant while the engine is warm. Follow the instructions, which usually say tap on the bolt a bit to set up vibrations which help the oil to penetrate. I would do this several times the night before I wanted to get to work and again before I started working on it.
Liquid Wrench works OK, Silikroil or Kroil from Kano labs works, something sounding like PB Blaster seems to be a favorite of some of the guys.
A broken bolt is a real PITA especially if you don't have any room to work in.
Remove the bolts carefully. Maybe a little heat from a propane torch may help.
If lord forbid you do break a bolt, let's hope it leaves eomthing to grab on to. Then various tricks can be tried. Some recommend heating the bolt til it is very hot and then touching a candle to the threads so they wick up into the rusted area. Some recommend welding a nut to the bolt and then removing.
If you have to use an easy out DO NOT break it, or then you really have a problem. Some recommend a reverse twist drill instead. They drill the hole and a lot of times will cause the bolt to turn out due to heat vibration, torque and luck.
If you do break the bolt, check this website for discussions on how to remove.
If ou do swap to headers, invest in a good set of aluminum gaskets or something similar. Unless you enjoy replace gaskets. I replaced 2 sets of regular gaskets and then went back with the aluminum ones and havent had an issue since. over 3 years on them now.
I broke 2 bolts today after using PB blaster and WD40 by both spraying when hot and spraying a week ahead of time for 2 or 3 applications.
3 of the bolts had already broken off on their own so now I'm looking for options since drilling with a right angle drill is tough since we cant get a lot of leverage on the front bolts behind ths shock tower.
ANyone have any ideas on how to get them out? Can we torch them out?
Here's a pic to keep everyone from trying this at home