Re: Intro 1965 GMC K1502
 

Thanks, Ed. The rear block on yours looks like a 6” lift? Would you be able to measure? Thank you.

Re: Intro 1965 GMC K1502
 

Also, I see the rear lift on yours came with a stop extending out from the block to receive the axle bumper. Guess that’s missing from mine as well!

Re: Intro 1965 GMC K1502
 

Finally getting around to lowering the truck. Front down to factory specs and rear lower by 2". Dual exhaust going in shortly. Any favorites when it comes to mufflers?

Re: Intro 1965 GMC K1502
 

I'm sure everyone has their favorite, so you may get a variety of opinions. This may not be relevant, but years ago I had a '66 Nova with the 350 HP L79 engine. It had Flowmaster 40s on it when I got it. The droning noise and resonance at certain RPMs was so bad I had them replaced with Magnaflows. No more headaches! I can't say the Magnaflows were much quieter, but they were certainly less annoying.

You might find this comparison interesting: http://exhaustsystemsguide.com/magnaflow-vs-flowmaster/

Re: Intro 1965 GMC K1502
 

Thanks for the tip, Ed. Much appreciated.

Re: Intro 1965 GMC K1502
 

You can read a lot of other opinions too, on this site: https://www.bangshift.com/forum/foru...-vs-flowmaster

Many of them comment on the annoying drone of the Flowmasters that I experienced at highway speeds.

Re: Intro 1965 GMC K1502
 

Thx again, Ed. I’m going to go straight out the back with a smaller pipe (2 1/4 or 2 1/2). Also, not sure I’ll be doing any highway driving so think I’m going to try the 40’s and work my way down if I find them too loud.

Re: Intro 1965 GMC K1502
 

Give the 40's a chance, I run the 50's on my truck not bad at all on noise and drone, I'm considering 40's for a bit more aggressive sound, running 2 1/2 inch pipes.

Re: Intro 1965 GMC K1502
 

Will do. Thanks.

Re: Intro 1965 GMC K1502
 

We put DynoMax cat-back on our '88 Mustang GT 5-speed in about 1993. Stock exhausts didn't last then like they do now. Bad drone at highway speeds.

Keep in mind your V-6 is a totally different animal when it comes to exhaust. I'd start with what you think would be a quieter muffler and run it 10,000 miles and see how loud it gets. A V-6 is kinda the worst of 4 cylinder and V-8 combined into one. Definitely not a smooth quiet in-line six. Think I'd run 2-1/2" pipe to the rear bumper. Your 305 V-6 needs the exhaust of a 396 V-8. It's a Big block minus two cylinders and wants to rev up under load.

Re: Intro 1965 GMC K1502
 

Thanks! A Dynomax turbo muffler is also on the list but already started with the Flowmaster...by the way the truck just hit 15,000 miles after about 53 years....something tells me the next 10,000 will arrive much sooner!
Thanks for the muffler feedback all!