Reference Manual

Chapter 9: Exhaust: Hooker Dual Outlet System

Article by: Tom Lentz

Hooker G-Body Exhaust

I've had a lot of questions about the exhaust system, so here's a look at the install of the Hooker cat-back exhaust, part number 16810. Sells for about $270 from Summit Racing. It's a 2.5" cat-back system listed for the Monte SS or Buick GN.

The system exits behind the rear tires like the stock H/O, 442, GN, or GNX system. It's not a bolt-on with the '84 Cutlass because of the catalytic converter attachment (NOTE: all 307 G bodies used the same front converter flange. - Ed). To fix this, I had a flange welded onto the front of the test pipe to mate with the one on the stock manifold pipe ($20 at the local machine shop. Take a tracing of your cat flange down with you, or just have them weld on a 5x5" flange and you drill the holes when it gets home)

Click Here for a sound recording of this same Hooker system on Tom Martin's Cutlass (with a stock '77 Olds 350, computer controls intact). It's a little large, about 433k, so be warned. I think it sounds wonderful. It gets a bit louder with age (due to the packing material getting dirty/compressing/blowing out), but it's not loud at all. Some people (mostly GN owners) complain of resonance/droning problems with this system (maybe because they have a turbo?), but I haven't experienced any. If you do, the Walker Ultra-Flow muffler is supposed to be the best cure.

The 2.5" pipes have not hurt low end power at all, and really help the top end (freeway speeds). Also, it boosted me by 2mpg highway from 17 to 19mpg! My cat that I took off was not visibly plugged either.

This is the Y-pipe at the rear of the test pipe (which replaces the cat). I highly recommend finding some stainless steel bolts and nuts here, and on the front flange too. Yes, I know my front tranny seal is leaking. It's not nearly as bad as it looks. Thanks for noticing :-)

Muffs hung and in place.

Right tailpipe, mounted.

Right tailpipe, rear under car view. See hanger welded on at the right side of the picture. Where it's mounted to the frame is obscured by the spare tire well.

Left tailpipe, same view as from right side. Note how high up the mufflers mount! Of course the rear suspension is fully extended here since it's up on jack stands.

Full view from rear, still up on jack stands. BTW, like my poor man's creeper? I have a real creeper, but I like using scraps of carpet better.

Out in the daylight, not on jack stands. I lightened up the area of the picture under the car to see details. Unfortunately there's no details to see! The muffs are in front of the axle.

Side view. Note the daylight under the car, rather than the mufflers hanging down :-) It's too dark to even see the tailpipes in this view. Directly under the side mirror you can see the tip of the flange for the test-pipe. The catalytic converter would hang down at least this far.

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