I am replacing the exhaust on my '71 Slant.

What are some of the issues that you folks out there have ran into doing the same?

Anyone have any good tips?

Are you changing the exhaust manifold or just the exhaust pipes?
DD

Just the exhaust pipes. The manifold is in great shape. I just had the manifold gasket changed not too long ago.

I was thinking of going to a 2.25 pipe and a high flow muffler.

That is what I did this past August. 2.25" all the way back with the Thrush version of the Flowmaster 40 muffler for $32.00. Both Jeg's and Summit carry them. I actually bought mine from Summit. It really helped the overall power output especially for merging in traffic on the freeway and going up steep grades like on I-90 up and over the mountain pass. Lots more useable power!
The sound is very mellow and does not drone at cruise 2500 rpm which is 60 mph for me. If you run it up to 90 mph 3500 rpm, it roars!
My wife actually enjoys it! I just wish had duals and an "X" pipe with Doug Dutra's Dual manifold conversion!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Your intake and carb bore size and silenced or 'unsilenced'/open air cleaner can also have a determination on 'when' and 'how loud' your drone is... with 2" duals to the back my 'drone' starts about 2100 rpm and just gets louder until about 3000 then it just changes pitch with the rpms... (but long ram intake, 4 barrel and 2" with turbo mufflers just are that way...sure scares the fart can Hondas since I can 'out annoy them' when the secondaries open up...luckily occifer friendly looks for the 'fartboy' to give the ticket to and never thinks about 'that old 340/360 duster...')

2.25 to the muffler and 2" or 1 7/8" out will be fine...also, if the use a 'tubing bender' it will 'kink things when they make a bend so 2.5" might be better so the bends are actually 2.25" instead of bottle necking down to 2" every 30-90 degree bend...

-D.Idiot

Are you saying that by changing to a 2 barrel or a 4 barrel the drone will increase?

Currently I run the Super Six air cleaner with the Holley 1920 and have a dual snorkel stock air cleaner for the 4 barrel for when I make the switch.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Does anyone know where you can get the dual snorkel air cleaner aftermarket? I would like to find something like that for my 1bbl. Seriously, I would.

The 2 1/4 pipe from manny all the way out the back worked very good for my one barrel 1920 and stock engine setup. Although I used a Flowmaster and the drone is bit to deal with. Some people like that sort of thing, maybe I am getting a little old because I was going to get a turbo type muffler to install and quiten it down a little bit. As far as power & fuel mileage though its great.



Jess

Jess,

One of the guys up here mentioned that you could add a Cuda resonator pipe behind the Flow Master 40 and that will quiet it down alot. I haven't tried it, but thought that might be fun to try. It is an easy add on.

My friends Valiant has the same 2.25" exhaust as mine, only he uses a turbo and it is pretty loud. I think my Thrush chambered muffler is quieter. If you add the resonator which could be as simple as a short glass pack, quiets it down allot!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Yea that would be the easiest, and probably the cheapest. I have installed a class pack like a res before. I always kinda liked the mellow tones a turbo muffler gives though, but I havnt tried one on a /6. The Bumble Bee sound when WOT and pulling some RPM gets to me. I guess I have been spooled with Big Blocks for to long now.

For now i am going to leave it as is because a turbo system is going on soon. I will wait and see how much a change in tone I get then, plus it may get changed to a 3 or 4" exhaust anyway.


Jess

Jess,

I understand, I have two 440's, 69 Chrysler 300 375HP 5,000 pound hot rod and 72 Imperial with a 440. The 300 has great sound a growl. The 72 Imperial is like a limo and in great shape. Wish we could get that quality of sound out of the SL6's. Not many folks run dual exhaust and "X" pipes on the SL6 like we do on the big blocks. It would sure be fun to hear a SL6 set up that way though. I wonder if anyone on the forum has done that and recorded a sound clip we all could listen to..........

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG