Dual exhaust system for 85

[Fairlane514]

Great site and great information!

I did a search so I hope this isn't an annoying question that has been covered over and over.

I have a 85 with stock exhaust, Y pipe, huge catalytic, and dual tail pipes out the drivers side. It is a Goodwrench 350 and I want to put headers and dual exhaust on it myself.
I can weld so thats not a problem. Can anyone suggest a nice 2 1/2 system thats fits well, no drone but nice sound?

Thanks!

 

[Jason S]

Welcome to the site.

I used a dual kit from Dynomax with a Jeg's crossover and cheapo Thrush mufflers on my '73 K2500. 

The kit I bought was for manifolds, but they make kits for headers, 2wd, 4wd, etc.  It took a while tweaking everything and adjusting and checking clearance. It comes with clamps, so you could clamp it up and then tack weld everything, remove the clamps and then fully weld it.  I have yet to weld mine up, but haven't had any leaks with it clamped.

It had a rusted out dual setup with Mac mufflers before and had quite a bit of drone.  It doesn't have the drone, but I'm still considering swapping the out the Thrush mufflers.

[Fairlane514]

Thanks Jason!

[Fairlane514]

I'm having a real hard time finding 2 1/2 inch system, Pypes makes one that is stainless, but i don't need that here in Houston.

[454Man]

Here's what I did. Slightly less $$$ then a pipe kit. (2) summit 2-1/2 pipes four feet long like $30 (2) 2-1/2 heddman header xtentions that are 17inches long (2) 90 degree 2-1/2 heddman bends (4) walker exhaust hangers if needed I can lookup the parts and post links. Since you weld it will be easy. The passenger side header on mine was angled down a little, so to counteract I cut a angle about 5 or 10 degrees on the 4 foot pipe to angle it back up. That was it. Oh and I used summit race mufflers. The race model. Don't get them unless you want to be louder than everyone else

[ralphhemi]

I got a 2 1/2 Dual exhaust system for my 78 k 30 from  JC Whitney for about $200. It was made by Heartthrob looks great with all the clamps and hangers  NO mufflers

[bake74]

     You said you were from Houston, do they require for inspection that you put the catalytic converter back on the truck ?  That cat will affect performance and sound if you have to install it still, might want to keep that in mind if you have to put it back on.

[Fairlane514]

No catalytic required on 1985..........so that makes it a lot easier!

[78 Chevyrado]

Cats are required on all 1/2 tons (76?) 77 and up, and 3/4 tons 79 and up.  Thats federal standard.  Cali standards are usually higher.  IIRC, By 1985 or so even 1 tons had cats.

If you have inspections, you need cats.  otherwise you're good.

[bake74]

Cats are required on all 1/2 tons (76?) 77 and up, and 3/4 tons 79 and up.  Thats federal standard.  Cali standards are usually higher.  IIRC, By 1985 or so even 1 tons had cats.

If you have inspections, you need cats.  otherwise you're good.

     I know California sucks for vehicle laws.  But for now this is where my work is for the field I am in.  Ca. smog states that whatever the Manufacture has on the vehicle is required unless you get a EO (executive order) with carb (Ca. air resource board).  So that is why I am always asking about other places.  Trying to line up where I want to live when I retire.   

[Fairlane514]

After hours and hours of research, i think I put together a "kit" for a 2.50 inch system for manifold back.  I may not go with a header at this time, I am also wanting to lower the truck and that kit is about 650.00.

 These parts are all from Summit.....Two Summit welded mufflers (I think they are the same as Dynomax welded) 75.90 P/N SUM-633252
                                                      Summit "X" pipe kit P/N SUM-642125  89.95
                                                      Flowmaster tailpipes for 73-87 Chevy C10 P/N FLO-15803 129.95
                                                      Ball flange connector (to exhaust manifold) P/N WLK-41726 (female) two at 5.95 each (they also offer a male version) 41723
                                                      Two 90 degree down pipes P/N SUM-670176 19.95 each  or 45 degree down pipes P/N SUM-670175 about the same price.

I don't have the truck in front of me, so I don't know if I will use the 90 degree or 45 degree.......probably the 90.

Total is about 350.00-360.00 without shipping, but Summit is offering free shipping on the Flowmaster tailpipes.

 Still looking at other sources for kits, but this gives me 2 1/2, whereas all I have found is 2 1/4, unless I go stainless steel.
                                                     

[454Man]

Let me check my price list in the morning... maybe it might shine a little light:)

[Fairlane514]

Ok, definitely going with headers, I took the manifolds off today.

I like the Hedmans with the ball and socket style collector, so thats probably what I will use.

[Fairlane514]

I don't know how I missed it, but I checked Summit again and found a Pypes kit.  Its a 2.5 inch system from the "crossmember back" with no mufflers and exits out the sides behind the rear tires.  I picked the Summit Turbo mufflers offset inlet and outlet to complete it.

PYE-SGT79    299.99

[bake74]

      Everyone can say they have missed things that are right in front of them.