For those of you who do not know, I bought a set of Bassani Mid-Length headers to install on my 2002 1500HD w/ 6.0L & 4L80e. I picked up the headers new from SlvrSierra, the only problem is that they were P/N 531500C which is for the coated version of the headers for the 5.3L. For both the 6.0 and 5.3 the headers are the same, the only difference is the adapter pipes. So, I called up Bassani and ordered up a set of the 6.0L adapter pipes allowing me to pick up SlvrSierra's headers for less than full price and mount them up.

The version of the 531500C that I received from SlvrSierra did not have the EGR fitting, so I bought the GM EGR plug 12558346, and programed the EGR out of the PCM.

I installed the headers using Fel-Pro P/N MS92467 (i think that was the number). The old manifolds came out relatively easily, the head on the back bolt on both sides was broken off, luckily they came out easily with a set of vice-grips.

After installing them and getting the exhaust work done, I noticed a rather large exhaust leak. Turned out the header was resting against an ear that sticks out the side of the 4l80e. Unfortunately the ear had already done some damage to the header. I finally just sawzalled off the ear once I found out that that was the problem.




The exhaust adapters that I got from Bassani didn't fit worth a poo. I had to have the headers adapted by the exhaust shop who actually did a great job of fitting them up.

Drivers side, the discolored part is the Bassani adapter, the small silver section is what the exhaust shop added to get the parts to fit up. Anyone know why the Bassani adapter is discolored?? I am guessing that the Bassani adapter is stainless steel and the exhaust shop parts are aluminized pipe.




Passenger side adapted up. This was all built by the exhaust shop, I am really happy with quality of work they did.





Finally the moment you have all been waiting for, some pictures of the headers installed on the truck.







Forgot to mention, I installed GM studs and nuts as well. P/Ns are 11589154 on the studs, and 11609746 on the nuts.

Any questions, comments, let me know.

 

1 5/8th or 1 3/4rs ? They look great, what does the seat of the pants dyno say for power improvement?

 

looks good!

 

Quoted from the Bassani website

I actually like having chosen the smaller primaries, I am not after high RPM usage, I want a torque increase, and small diameter primaries do that by keeping the exhaust velocity higher than large primaries. No need for me to rev over 5500, 6k max.

As for the improvements, my butt meter says it is quicker especially from about 2500 on to the shift point. Although, it does feel like it is able to breathe better throughout all the RPM ranges. Never had headers before, so I don't really know what I should be expecting.

I also noticed a change in exhaust note. My exhaust volume went up probably 10-15% and I have a very slight hollow sound in the note, similar to what you would have with one of the loud flowmasters only very toned down. If you hadn't heard and driven with the exhaust before you wouldn't be able to pick up on the sound difference now. Once I got that damn exhaust leak fixed I have noticed no increase in underhood volume, I attribute that to the thick 14ga piping (i believe that this is thicker than most cheaper headers). If anything my under hood volume has gone down now that my factory manifolds are not leaking due to the rear bolts being broken off.

The dent in the tubes is my own fault, I had read about someone having clearance problems w/ the Bassani headers and 4l80e. I just figured I was lucky when they bolted up just fine, I guess I got lazy and didn't look around to see if I was hitting anything.

As for installing them, I have heard about long tubes being hard to install, these mid tubes were a cinch. Between the small primaries and their shorter size they practically fell into the engine compartment. I have mounds of clearance around them. I put them both in through the top, and without someone there to catch them they will keep on going and fall out the bottom. lol

 

Very nice looking, they look to be coated, are they? Also, what are they made of, stainless or mild steel? I really like the way the GM studs and nuts turned out too

 

Ceramic coated. Speed Engineerings website says they are mild steel.Yep, GM studs are nice, anti-seize on the head side, nothing on the nuts. Is that how I should be putting them on? Are the nuts reuseable? If so, how many times?

 

That's how I'd put them on, then if they give you any problems on removal, worse case scenario is the that the nut will stay on the stud and the stud will thread out of the head. I'd assume that you can re-use the nuts, although I'm not sure how many times they can be removed until the triangular locking feature widens out. As I sorta mentioned though, I wouldn't doubt that if you went to remove them that the studs would probably thread out of the head easier than the nuts come off of the studs.

 

That is true, when I had to pull the passenger side to fix the hitting issue w/ the 4l80e 5 of the 6 studs came out, only one came off and left the stud in the head. When I replaced the passenger side header I put anti-seize on the nuts before putting them back on. Just need to put anti-seize on the drivers nuts sometime soonish. From all I have read you cannot have enough anti-seize on exhaust parts.

 

I know this is an old thread, but I have been searching for these headers high and low. Can someone please tell me where to find them.