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Old 07-25-2024, 09:35 PM   #1
rambo84k2500
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Lightbulb 84 K25 Exhaust Opinion

I want to hear some opinions. Curious what ya'll think.

I currently have a 1969 327 small block in my 84 k25 high sierra.

Decided to put on ram horn style exhaust manifolds cause I needed something worthwhile that would fit my 4x4 chassis with mechanical clutch linkage, so I decided to keep it simple with new ram horns.

New ram horn had 2.5 collectors, so I had the exhaust shop put on dual exhaust.

Here's the opinions!

I wanted my truck quiet so I saw that squarebody trucks with the 454 came with quiet-flow 2.5 inlet/2 outlet mufflers. If that muffler is okay for a 454 should be okay for my 327. Now I have ram horns with 2.5 dual exhaust with 454 mufflers.

Well my local exhaust gave me some s*** for putting on those mufflers. Said it was to restrictive. My truck runs great and is quiet now. What you think. Curious. Are those mufflers to restrictive???
Down the road I'll put in a fresh 350, but even a stock 350 my exhaust should be fine, I think. I can always change to performance mufflers down the road.
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Old 07-25-2024, 10:02 PM   #2
jerry moss
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Re: 84 K25 Exhaust Opinion

those mufflers are fine. it'll never pass commifornia emissions test- i know you don't have to smog up there unless you are selling-YET. they are trying to pass laws so the entire state has to do the emissions test no matter where you live in this wonderful state. they are also mandating cameras on every smog machine to eliminate "clean plugging" on OBDII and clean piping OBDI. It's coming so be prepared. I work in a shop that does smog's and the state is really tightening the screws on this emissions crap. one other problem-it's illegal to install an older engine in any emission controlled vehicle.
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72 cheyenne super K20- tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,tow hooks,bumper guards,toolbox,aux. fuel tank,posi front and rear,plus other goodies!!! SOLD
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73/80 chevy/gmc K20 SB400,turbo 400,205,tilt,a-c,gas hog.
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Old 07-26-2024, 09:25 AM   #3
Dead Parrot
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Re: 84 K25 Exhaust Opinion

Unless this is a race truck, don't worry too much about the mufflers being restrictive. It they are OK for a 454, they should be great for a 327. Sounds like you wanted quiet as a main objective and have achieved that goal. Could be your exhaust guy is in the "Louder is Better" crowd.

As mentioned, if you are subject to emissions, I think your truck probably came with a converter. Probably one of the older style very restrictive pancake types. Something to investigate and be prepared to deal with. Better to have a plan and not need it then be told to park the truck until you do thousands in corrective restoration to OEM config.
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Old 07-26-2024, 06:33 PM   #4
rambo84k2500
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Re: 84 K25 Exhaust Opinion

Didn't know how much you guys love smog laws.

My truck passed this summer in socal no problem cause of a few reasons.

My truck originally is an federal camper special 3/4 ton truck, so in the smog book all I need is a smog pump with heat riser exhaust manifolds and that's it. No EGR, No EVAP.

Yes my 327 block is from 1969 but I got 80's smog heads on them with an non-egr 70s intake. My smog guy didn't hunt for block numbers cause visionally everything was there and looked original. I kept all original smog equipment if I ever have to smog again, but that's far from my concerns cause I'm moving out of state soon. When I move those smog parts with be for sale or I'll give em away.
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Old 07-28-2024, 01:17 PM   #5
kwmech
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Re: 84 K25 Exhaust Opinion

The 2.5 into a single 3 would have been more than enough flow and probably given you a better tone. GVW rating on the 3/4 ton will give you better info on the smog required
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