Exhaust

[Quigley]

I was wondering about if changing from a stock single factory style exhaust to a bigger dual system will show a worthwhile performance gain. Truck is a 305E with a 500 Holley and Pertronics ignition, Powerglide and 3:07 rear gear. Just seems a little anemic to me. Thanks, Dave

[TJ's GMC]

Worth while gain fer sure! Also sound WAY better!


https://www.youtube.com/watch?v=RCfanx30JO8


https://www.youtube.com/watch?v=qtTxJ_KEFhs

[FetchMeAPepsi]

Paragraph 3 here tells you exactly what works best.

http://6066gmcguy.com/performance.html

[bigblockv6]

The dual exhaust will definitely help specially running the larger Holley 500but with 3.07 gears you may want to consider an upgrade to 3.54 gears as well specially with that Powerglide or PowerFlow as GMC called it

[TJ's GMC]

Originally Posted by FetchMeAPepsi

Paragraph 3 here tells you exactly what works best.

http://6066gmcguy.com/performance.html

Justin's truck sounded great. Has flowmaster 50's. I have the 40's.

[bigblockv6]

TJ, Justin's truck did sound great but unfortunately someone talked him into converting to a small block Chivy 350 I met briefly some 12 years ago when buying some parts from him, I saw the truck but he pretty much stayed clear of talking about it

[TJ's GMC]

Originally Posted by bigblockv6

TJ, Justin's truck did sound great but unfortunately someone talked him into converting to a small block Chivy 350 I met briefly some 12 years ago when buying some parts from him, I saw the truck but he pretty much stayed clear of talking about it

Now that is heresy. lol

[GMCNUT]

Originally Posted by bigblockv6

The dual exhaust will definitely help specially running the larger Holley 500but with 3.07 gears you may want to consider an upgrade to 3.54 gears as well specially with that Powerglide or PowerFlow as GMC called it

I'm with Pete here - 3:54 gears were usually installed behind a Pow-R-Flo trans so changing from 3:07 to 3:54 would be a better boost I think than the exhaust but doing BOTH would be great too! Good luck

[Clarke]

I have a funny story/embarrassing moment... When I went and looked at the truck that I purchased I asked the guy what the best way he found to start this truck (seems every old motor has a preferred way to start)?

I was standing by the drivers door, which was open and i was next to him... The hood was still up from when I was checking things out... He turned it over then looked at me with a blank look... I thought he was embarrassed because it didnt start on the first turn... I asked him to hit it again and he said it was running... I didnt believe him until I looked under the open hood and saw the fan blade turning...

I told him id have to fix that. It still had the stock exhaust. For several years i ran it with single in dual out through Flowmaster 40. Then I swapped the 40 out with a 10 several years ago. With the stock tranny and running 4.10 gears the exhaust is not as loud as you would think with the 10. I like it, and at least I can tell its running without looking at the fan.

[TJ's GMC]

Originally Posted by Clarke

I have a funny story/embarrassing moment... When I went and looked at the truck that I purchased I asked the guy what the best way he found to start this truck (seems every old motor has a preferred way to start)?

I was standing by the drivers door, which was open and i was next to him... The hood was still up from when I was checking things out... He turned it over then looked at me with a blank look... I thought he was embarrassed because it didnt start on the first turn... I asked him to hit it again and he said it was running... I didnt believe him until I looked under the open hood and saw the fan blade turning...

I told him id have to fix that. It still had the stock exhaust. For several years i ran it with single in dual out through Flowmaster 40. Then I swapped the 40 out with a 10 several years ago. With the stock tranny and running 4.10 gears the exhaust is not as loud as you would think with the 10. I like it, and at least I can tell its running without looking at the fan.

Now that's a funny story! I will say I have seen some videos where you can hardly hear them running.