I worked for FLP for 3 years and my car was used as the prototype for the LT1 long tube header. I have seen many header installations over the years on various f-bodies. LT1s and LS1s. I have seen header installations on very low mileage cars (meaning basically brand new motor mounts) and the steering shaft would rub on the header tube. This is attributed to the varying tolerances that the f-body has... remember it's not a Cadillac. So I don't buy into of the theory of the motor mounts getting hot and wearing out. I don't know how many miles were on turbo_z's car, but I would think that age of the motor mounts had more to do with it. Before you go through the time and expense of replacing the motor mounts... do it the easy and expense free way. Originally... my headers fit fine. But with the addition of the Canton oil pan, I had to pry the header away from the oil pan to get a little more clearance that I wanted. By doing so, the header was now closer to the steering shaft. I did my little trick... loosen the bolts, pry the header, and re-tighten. All fixed.

If your y-pipe is close to the floor board, you can remove the heat shield on the passenger side to get a little more room. Also... you can use a pry bar (with a piece of rubber hose on the pry bar so you don't scratch the coating on the y-pipe) and pull down on the driver's side collector area to get the added clearance. Make sure to re-tighten the header bolts on the driver's side after doing so.

Also, try replacing the transmission mount with a poly mount. The stock mount is rather soft as allows for a lot of flex. If your y-pipe is banging, this will cure the problem along with a little tweaking of the y-pipe.

Trust me on this... I know what I am talking about. I may not know everything in life... but this I am sure of.

 

Do I have to remove the plastic piece right under the steering wheel to see those 4 bolts or are they visible just like that?

 

Yes you do. Not a big deal.

 

Mine rubbed the steering shaft bolt also, and that's with new poly motor mounts. It stopped rubbing after a day or so of driving and about 6 or 7 weeks later it still dosn't show any sings of rusting. I may adjust the column slightly anyway though, just to be sure it has enough clearance while under load and the motor twisting.