I have a 1998 chev c2500, 350, automatic, 4.10 rear end, that I use to tow a 30' 5th wheel camper. I get 9-10 mpg. Has anyone ever done or read about a test where they compare performance with stock exhaust,
cat back exhaust, headers, etc. I know it could sound better, but I wonder if modifying the exhaust has any real benefit.
thanks.
frank

 

There are a bunch of opinions on who makes the best exhaust. In a towing vehicle you need to keep as much torque as possible so don't go with some huge free-flowing system which will rob all your backpressure and torque. I have a 1998 GMC 2500 with a 454 and went with a simple Magnaflow muffler replacement. The rest of the system is stock. I can't really say it made a difference besides sounding better (not too loud just a nice deep note). My old truck was a 2001 Sierra 2500HD with a 6.0 and I had a flowmaster 70 series towing muffler on it and it was about the same. The Magnaflow is quieter inside the cab though. I was told it has insulation to keep the noise level down inside the truck. Whatever it is it was exactly what I was looking for. Good luck! How does that 5.7 tow the 30 foot trailer?

 

It does pretty well, but I live in Florida. I have towed the camper thousands of miles, even into Canada, but I try to avoid mountains. I changed from a 3.73 to 4.10 gear.
Just looking for ways to gain some without losing anything.
Thanks,
Frank

 

Mr. Shamrock,
What do you haul with your 454? Is that throttle body injection? What kind of mileage? Automatic?

Thanks.
Frank

 

This is a vortec multiport injected motor w/ an automatice 4L80E. I had a 454 throttle body motor equipped truck before this and this one seems to pull a lot better. I usually tow a 20 foot motorcycle trailer with 5 or 6 bikes on it and one in the bed of the truck. It is more truck than I need really but I have always tried to have a truck with power and brakes to spare. I also have a 2000 model with the same motor that tows our pontoon boat. It has the 4.10 rear compared to 3.73's in the 1998. That makes a big difference especially in the mountains. The gas mileage is not that bad considering the power I have. It gets about 12 empty and 10 with the fully loaded trailer. I am willing to pay a few more bucks in gas to know that my truck is right for the job. Especially when the whole family is in the 2000 going to the lake.
I am also originally from Florida and never thought twice aboue using a 350 to tow, but when I moved up here 5 years ago my 350 equipped suburban just didn't give me that "I got this" feeling that the big block does.
When money was a little easier to come by a few years ago I was driving a 2002 Crew Cab 2500HD with the 6.0 and it was a very good package for towing what I tow. The 454 has a bit more power, but the 6.0 got a couple more miles to the gallon. I just can't afford the newer trucks anymore. When I first bought it the previous owner had a pair of flowmaster 2 chamber mufflers and the truck was obnoxious and gave me a headache on the ride home from picking it up. The next day it went to the muffler shop and after trying a couple different mufflers ended up with a single (2 in 2 out) 70 series flowmaster. It felt stronger after the new muffler was installed and sounded MUCH better in my opinion.

 

my 1998 Chev 350 vortec has developed an intermittant miss under light load especially while warming up. The ignition is all good and no codes set. It runs great when warmed up. The word is that it is sticky injectors and that running high octane fuel for awhile will cure it. I tried a can of seafoam, but no results yet. Any thoughts?

Thanks,

Frank