Calspeed headers....

[01hoe]

Anybody here using the calspeed lOng tubes? Web site says they are for 2wd models but people have modified to fit 4wd models. Wondering what modifications need be done for 4wd fitment

 

[MurdrNali]

We installed a set on my brothers 05 Sierra 4x4 a couple months back. There a nice looking piece with good welds and thick flanges. Price is great too but 4wd fitment is ehh. Had to clearance the front primary to clear the steering shaft a little bit but the bottom side was the big issue. Lots of pounding with a BFH to clear the driveshaft and u-joint. If you don't mind beating on a brand new set of headers then I'd highly recommend them. You'll never see the "massaging" on the bottom side anyways and everything else fit together perfect.

 

[Anonymous]

I'm too tired to use tact here, so I'm going to be blunt.

What is the point of installing headers when you are just going to beat the primary tubes closed? You lose almost all tuning and scavenging on that bank, and closing off the tube increases back pressure, increasing cylinder temperature, causing hot spots, and possibly detonation.

If you have to modify headers to fit, you must cut and reweld the tubes so they stay full diameter without kinks or sharp transitions. Keeping all the primaries the same length is also important. If you don't do this, you are better off just going with shorties.

 

[livingez_123]

I would have to agree with Anonymous.

 

[MurdrNali]

Maybe I was too blunt in my previous post as it seems you think we completely close off the primaries. The top side might have been clearanced an 1/8 in. The bottom side maybe a 1/4 in. I have no doubt that this changes the scavenging effect and flow characteristics of that primary but if you think it flat out ruins the performance of the header then I'd have to disagree, especially when compared to shortys. Just my $.02