Technical Information 


Yes! After more than a year of effort in finding a competent manufacturer, we finally hit paydirt in the year 2000! The winter of 99 - 2000 the prototypes, manufacturing jigs, and assemblies were completed and The Other Guys Performance and Exhaust Products are making these 3800 Series II headers today! 

The Other Guys have been instrumental in design and manufacturing for almost all the major header companies since the 60's! 


  • 1997-Current Grand Prix GTP
  • 1997-Current Regal GS
  • 1998-Current Bonneville SSEi
  • 1997-Current Grand Prix GT
  • 2000-Current Monte Carlo SS
  • 2000-Current Impala LS

The 3800 Series II development

With a little persuasion, these guys realized the performance and market potential of the 3800 engine and agreed to kick off their product lineup with the 3800 headers!  These photos are of a set bolted to a test engine for photo purposes, awaiting installation on the THRASHER "So-Lo" show car. Note that the production flex connector differs from this early prototype.

Some of you seasoned racers may recall that THRASHER had an entirely different header design on our Regal GSX development car in the winter of 1999 - early 2000.  In a nutshell, we could not find any manufacturer willing to produce the previous design at a reasonable cost due to the complexities of mandrel bending the 3 inch pipe accurately to ensure proper clearance and fit.  Another factor in changing from the previous design was the CARB EO certification process and almost all our email indicated everyone seemed to want the "3 into 1" header look. This plus the visual appeal of the high luster finish really knock your socks off when you pop the hood! 

Why Choose These Headers?


The original 3800 headers built for
THRASHER's "So-Lo" Show Car!

These headers will only be available in the high luster electro-less nickel plating shown in these photos.  The finished headers are dipped (not sprayed) so the plating completely covers all surfaces both inside and out which greatly increases corrosion resistance.  The Other Guys have repeatedly stressed that is the highest quality finish available for exhaust products and and will not deteriorate from excessive heat, unlike many other coatings available today.

Also, it is important to note that these headers are manufactured with 14 gauge tubing and all OEM style flanges throughout. Notice also the special flex connector at the downpipe which allows freedom of movement from engine vibrations.  The output is 3" and slips perfectly into the original catalytic convertor for easy welding when the stock downpipe is cut off at it's junction.  

Unlimited Lifetime Warranty

These headers are of the highest quality and the Other Guys are so confident of their workmanship they offer a Full Unlimited Lifetime Warranty against defects and damage, "even if you run over them with a truck" - their exact words, not ours.

So the bottom line is ... what are the performance gains for these headers over the stock exhaust manifolds? 

Dyno testing of  the development car before and after and have reported the following:  These dyno tests were performed on a bone-stock 2000 GTP as delivered off the showroom floor with 3000 miles on the clock, with absolutely no mods whatsoever! 
CLICK for full view of Chart!

That's right - stock pulley, stock exhaust, stock air intake and stock paper air filter!  This GTP produced a respectable 190 HP at the wheels in stock trim, typical of most showroom stock cars.  With the only change being the headers, still running into the stock cat and mufflers, this GTP showed a phenomenal 18HP and 16 Ft-Lb gain at the wheels!  Furthermore, the maximum boost level dropped to 6 psi (remember, this is the stock pulley)! 



Imagine the gains once the THRASHER Modular or Press-On Pulley is added to get boost back into the 10-11 psi range, and further refinements are made such as a cat-back free-flow exhaust and THRASHER Cold Air Kit and more are added! Check out our POWERPAKS for the best performance packages around!


            The Other Guys Headers
            Exhaust Headers
for FWD 3800 Series II___Direct from THRASHER ___$724.99 + S&H
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