Shorty header questions

[Musicars]

I have to replace the motor on my '06 Denali and figured since it was coming out anyway it might be a good time to put some headers on. Although I would prefer long tubes, I'm thinking of shorties for now just to avoid the fitment issues. I hear and read some don't fit AWD/4WD very well, there are clearance problems, some have cats and some do not which require more work to delete programming, etc. all stuff I don't feel like dealing with.

In looking at shorties I noticed that some have both sides with flat flanges where the Y-pipe connects (like my originals) and some have a built in donut on the right side only. It looks like either version would fit and you just wouldn't need a separate donut gasket on the right for the one that is built in. At first I thought it might be a difference between 5.3L and 6.0l but in reading most application charts it looks like both motors use the same manifolds.

Anybody have any input on fitment regrading the different flanges?

 

[01DenaliHiker]

I have to replace the motor on my '06 Denali and figured since it was coming out anyway it might be a good time to put some headers on. Although I would prefer long tubes, I'm thinking of shorties for now just to avoid the fitment issues. I hear and read some don't fit AWD/4WD very well, there are clearance problems, some have cats and some do not which require more work to delete programming, etc. all stuff I don't feel like dealing with.

In looking at shorties I noticed that some have both sides with flat flanges where the Y-pipe connects (like my originals) and some have a built in donut on the right side only. It looks like either version would fit and you just wouldn't need a separate donut gasket on the right for the one that is built in. At first I thought it might be a difference between 5.3L and 6.0l but in reading most application charts it looks like both motors use the same manifolds.

Anybody have any input on fitment regrading the different flanges?

Coming from someone whose made this mistake. I ordered the EGR-less shorties since I've deleted mine, those come with the donut style collector flange. EGR headers are the flat style. I ended up cutting and grinding the donut flange off to match up with my factory 01 Denali pipes. It was tons of fun. Lol.

If yours is like mine, don't get the donut flange one! Unless you enjoy cutting and grinding to make things seal.

 

[01DenaliHiker]

Remflex gaskets and ARP bolts while you're at it too.

Need a seller for the remflex gaskets? I broke two manifold bolts on the driver side trying to take them out, outer two (of course), zero exhaust leaks. My mind is blown. Worth every penny!

 

[Musicars]

Coming from someone whose made this mistake. I ordered the EGR-less shorties since I've deleted mine, those come with the donut style collector flange. EGR headers are the flat style. I ended up cutting and grinding the donut flange off to match up with my factory 01 Denali pipes. It was tons of fun. Lol.

If yours is like mine, don't get the donut flange one! Unless you enjoy cutting and grinding to make things seal.

Thanks for the info. I guess I assumed they used a donut gasket between the y-pipe and flange. By the sounds of this they must use a flat gasket. I have not had mine apart yet so I have not seen how they connect. I only have the manifolds that came with my replacement motor which have flat flanges. I didn't know about the EGR/NON EGR difference.

 

[drakon543]

always verify what you have with what your buying. if what you have doesn't have a particular aftermarket option your only going to see the option you don't have. good arp bolt kit and a quality gasket will be beneficial too as stated. the bolts that come in the kits are usually junk along with the bolts.

 

[01DenaliHiker]

Thanks for the info. I guess I assumed they used a donut gasket between the y-pipe and flange. By the sounds of this they must use a flat gasket. I have not had mine apart yet so I have not seen how they connect. I only have the manifolds that came with my replacement motor which have flat flanges. I didn't know about the EGR/NON EGR difference.

I didn't either, figured they'd just work the same, but it proved me wrong when I opened the box. Added some extra time to the install.