1994 GMC K1500 MUFFLER??

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Vettepilot

OBS Enthusiast
Joined
Jun 27, 2021
Messages
82
Reaction score
44
Location
Arizona
Hey guys,

I'm working on a 1994 GMC K1500 4x4 with the 5.7 engine. It's fully optioned out with ALL the heavy duty options fortunately. Eventually, it will get a fresh, warmed over engine with headers and true dual exhaust, but for now I'm just doing some much needed maintenance with a few upgrades here and there, and putting it back on the road. I bought it not running, and needing lots of various things repaired. I've thrown a new timing chain in it, rebuilt the throttle body while doing hi perf mods to it, and added an adjustable fuel pressure regulator. A hipo fuel pump is next, etc., and it's had a complete tune up.

Anyway, I was working under it this evening, and was wondering about adding a free-er flowing, more agressive sounding muffler for now. The single unit that is on it is a monster. It's a great big round unit, but here's the odd part--> it's got 2 3/4" inlet and outlets. No typo; 2-3/4 inches. I've been doing this stuff for a long time, but I've never run into that size before.

Does anyone make performance mufflers in that size??

Thanks,
Vettepilot
 
Last edited:

Erik the Awful

Supporting Member
Supporting Member
Joined
Aug 9, 2019
Messages
7,873
Reaction score
16,227
Location
Choctaw, OK

OutlawDrifter

Long Roof K2500 Driver
Joined
Jan 22, 2016
Messages
1,152
Reaction score
2,243
Location
KS
A 3" OD pipe will slide over the 2-3/4" factory exhaust. The 20" case Dynomax Ultraflow makes a great muffler for a DD. If you want more noise, just use the 14" case unit. I had a 1995 Sierra that had headers, no cat, Y'd into a single 3" muffler with a 14" case Ultraflow. Sounded great, but was a little loud on the interstate.
 

Vettepilot

OBS Enthusiast
Joined
Jun 27, 2021
Messages
82
Reaction score
44
Location
Arizona
Ok, thanks. I did find some mufflers. How much does the sound change with the factory muffler just by removing the cat?

Vettepilot
 
Top