My car has 140 thou on her right now. So far (knock on wood)...nothing has gone wrong with the motor...still nice and strong. The only minor lil prob i have at all is a small valve seal leak that gives a tiny puff of blue smoke when you first start the car cold....soon as it warms up it goes away. I was looking at a set of SLP intake runners...and possibly headers. Would this be a decent thing to do?....or should i just leave it stock and either sell it after a little while or wait for the motor to die? I have the 5.0liter LB9 TPI motor. Thanks.

 

Forget the runners, they are a worthless waste of giga$$$$ in your situation, and are of questionable value even for a 350, unless other significant mods are done to the intake system.

Go with headers first, and fix the valve seals (an extra half hour or so while it's far enough apart to do headers); then a better set of gears, I'd suggest 3.42 at the most; and possibly swap the injectors for a set of used ones out of a Mustang from some one of those people that's swapping them out for larger ones, and send them to Rich at www.cruzinperformance.com for service; and as always, head porting.

 

i would go with headers...

 

I'd say headers and a cat-back would be a good idea.

 

Do the exhaust work, then port the intake plenum behund the throttle body. As long as the plenum is off, you might want to match the runner openings a little better than the facctory fitment. with the plenum removed, pulling the EGR valve and clenaing the passages at 140K might be a good idea.

And it would be good to take RB's advice. While the TPI is apart, pull the injectors and send them for cleaning and flow-matching. At that kind of mileage, it might feel like a new engine with a good set of injectors. For ten bucks apiece, I wouldn't even think twice about it.