Opinions on original Flowmaster 40 on 350 w/headers

[mcintyrederek]

Hi,
1986 C10 LWB with a Goodwrench 350 crate engine, supposedly the 260 HP version (like you can get from Jeg's, etc)..  Edelbrock 1405 600 CFM carb with stock iron intake.  The truck runs excellent and is plenty powerful, and it's my daily driver.  Up until now, I've been running stock iron exhaust manifolds, straight down and back, to some sort of no-name mufflers and out the back.  No crossover pipe, no catalytic converter.  All pipes are 2 inch.

The collectors on the iron manifolds finally gave way, and since headers weren't any more expensive than old iron manifolds, I bought some.  They're full-length tube headers and they installed perfectly.  I have a reducer to take it down to the old 2" pipe that is in good shape.

A friend of mine sold me some stainless steel Flowmaster 40 "delta series" mufflers with 2" offset 2" center, just like I needed.  I am not into racing/performance/high flow so I don't care to upgrade to 2.5 or 3" pipes..  That being said, this is a general question..  I need some opinions on whether this would be the right choice for noise..  Like anyone else, I'd love for the truck to "sound good" but I don't want to be obnoxious or draw attention.  Furthermore, I don't want the cab noise to be high, either.  Before I have my muffler guy weld all this up, is anyone running these type mufflers on a small block with headers?  Going from stock iron manifolds to headers, will this increase the noise level out the back or just change the "tone" ??  Should I install a crossover pipe, will it be necessary, or no?  In general, I'm asking if this setup will be too obnoxious or will it give a good, decent "muscle car" tone that we're all looking for?  Opinions, please.  Thanks..

Mack.

[travisr1988]

Headers will increase your noise level as they are thinner than the cast iron manifolds, and use an crossover to help quiet it down some, I used an h-pipe crossover on mine and it was noticably quieter than same exhaust without it, but the headers are noticeably noisier than manifolds. Also be sure to run full tailpipes of you want quiet.

[Irish_Alley]

read up on this
http://forum.73-87chevytrucks.com/smforum/index.php?topic=32285.0 page 2 has some data you might like

[jg1977c20]

i have had flowmaster 40's on my c20 for about 2 years and honestly they sound good outside - they do draw attention but nothing from cops yet ,but the tone of the noise is getting old and i am planning to got to the 50 series ,from what i read on another post the delta series were suppose to be alot better but one owner also doesnt like the noise -personally i like the cars that are a little quieter and then leave you going WTH when it launches down the road

[mcintyrederek]

I saw a video here:

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

Which is nice to compare.  No idea what sort of compression the engine has but gives you some examples.  Based on what I have read here and other places, it looks like I'll have no problems with the 40 Delta series, if I put a cross-over pipe close to up front to kill drone noise as much as possible.

Thanks for the replies,
Mack.

[mcintyrederek]

I got the 40 series Delta Flows on today.  Forgive the blurry picture but this is how I did it.  I know the crossover pipe probably should be up closer to the collectors but then I'd risk not being able to remove the transmission from the bottom had I done that (without cutting the exhaust up again.)  These are full length headers running into a 3" collector..  Then from there is reduces down to 2" (I know it's small but I'm not looking for a lot of performance.)  It hits the crossover pipe and then the mufflers are tucked up underneath in FRONT of the rear axle, then tail pipes straight out the back. 

I fired it up and took it for a spin and it sounds GREAT.  But... with the back glass open and the window down, there's still drone noise (a lot) ...it's not unbearable but it wouldn't be fun to ride in for a few hours at a time..  which I don't do much anyway..  just wondering, is there anything else that would help with the drone noise?  Undercoating the bed, cab, or anything...  anything other than taking the 40's out and replacing them with 50 series?

Thanks,
Mack.

[travisr1988]

You can try resonators, but likely changing the mufflers is the only way to get rid of the drone.

[roundhouse]

You try the mufflers you had on it before ?


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[mcintyrederek]

No..  the guy at the muffler shop (good friend) thinks I'm peculiar anyway, I hate to ask him to cut the Flowmasters off and put the other ones on.  The ones I had on before were VERY quiet out the back but still had drone noise in the cab.  They were some sort of Walker Sound-FX chambered mufflers that were a little too passive for my taste.  I wanted something a little more aggressive and I'll be darn if I didn't get it.  Probably could have put them on in place of the Delta 40's and it would have been perfect with the headers. 

I'm going to experiment with sticking some sort of tubes in line right after the crossover pipes.  Some Jones Full Boar tubes aren't that expensive and would be easy to stick on and test, especially since the collector bolts are brand new and easy to take off.

Mack.

[warwagon85]

Just replaced the exhaust on my 85 short bed.  My old set up had some old no name headers and no name mufflers with dual cats, 2 inch set up exiting just before the rear wheels.  I replaced headers with a set of Hooker headers, new colllectors, 40 series Flowmaster with 2.5 exhaust exiting before rear wheels and no converters.  I'm very happy with my set up.

[mcintyrederek]

Looks like a really nice job.  I think not having the carpet/padding in the cab is really what's getting me.  The exterior sounds fine but the interior is just loud.  I think I'm getting used to it, it doesn't bother me as much as it did before.

Mack.