Muffler Ideas for 505.

Anyone have exhaust building experience with a setup like I have here? It's a 505 for my Ramcharger, the headers are 2" primary mad dogs, with 3.5" collectors. I need to come up with a muffler that won't smother the engine but also isn't crazy loud since the truck will be on 37's, so the exhaust will be at car window height.
Engine: 505, trickflow 270s, 550 ish cam hydraulic roller, indy dual plane, 10:1, 950 cfm carb.
I have total length of 48" to fit it all into, and on the outside of the frame I have about 10" between the parking brake brackets and the middle of the rocker panel.
Should I neck it down to 3" and the go with the longest round muffler I can find, or go with a 20" normal round and put a spiral silencer in the middle? Ideas?

I run 3 1/2" collector neck to 3" then use Hooker Aerochambers in front of diff.
505 , tf270 heads , Dougs headers
Works for me not excessively loud at lower street rpm, ok wide open .

Tex

I have 2 cars, both with 505”. Close in power. One dynoed at hair over 600 hp and maybe the other 650-660 hp based on track/ weight /et-mph comparisons with eachother. Both just about 10.4 and 10.6:1.

1 has 2” hookers into 3” ex and x pipe using Dynomax Ultraflo 3” mufflers. Sounds good.
The other 1-7/8” hooker headers into 2-1/2” ex with x pipe and into Magnaflow stainless welded mufflers. Both dumped at axles. The Magnaflow system, even though smaller and slightly less power, sounds better to me. Just has a nicer sound to me. Both perform very well in car.

At track, the Magnaflow system lost .15 et and 1 mph in back to back testing same day within an hour of eachother.

I would run a Dynomax Ultaflow and possibly run a glasspack in front of it.

I’m at the exact same point. I purchased the Mad Dogs for my 77 w150 that has a 528. I haven’t build a street vehicle for years so I’m clueless on muffler options to keep this thing quite. Do you have standard cab and short box? Hopefully I’ll have a little more length to work with as my truck is a Club cab. Didn’t you have header clearance issues with the shocks? How did you fix that? Sorry to rob the post.

Pypes racepro. Fairly quiet until you stand on the loud peddle.

The quietest straight through muffler I've found is Pypes race pro. Much quieter than Magnaflow and Ultra Flow.

Edit-carnut beat me to it, agreed

i have heard the auger/spiral inserts don't do much but make your wallet lighter.
i read a test about those years ago, but i can't remember where.
perhaps others can chime in with real world info on that style of insert ?

On (2) W150 I did 2.5" exhaust pipes. Passenger Side pretty much straight back with a slight offset around the transfer case. The Drivers side went back and crossed over to the passenger side behind the transfer case then ran parallel to the other exhaust tube. one had dual turbo mufflers side by side, the other used a dual 2.5" inlet, single 3" out baffled muffler. I don't recall the muffler brand, it was a smaller brand name, and it may have actually been a 3" in, dual 2.5 out installed backwards? I sounded good with a warmed over 318?
Because these were the trucks with drivers side fuel tank, the muffler(s) were on the passenger side. The '84 RamCharger had the rear mounted 35 gallon fuel tank, so I think there is room for a muffler on the drivers side?
If you are using that rear mounted fuel tank, I would modify it to limit fuel slosh (Fuel cell foam or baffles.)
I had about 20 gallons of fuel in my tank, and took a corner a bit to fast, and the fuel slosh kicked the back end loose, then when I went to correct, it sloshed the other direction and spun the 95" WB truck around. Rear tire caught a curb and tipped the Ramcharger over onto the side.

I think the Muffler Brand used for the dual inlet single exit was IMCO? When I looked it up, it seems to be Cherry Bomb?

It's a Ramcharger, so half foot shorter than a short box. There is no goo way of going back inside the frame so everything will be on the outside.
I read the reviews on the Pypes bullet mufflers and it seems they muffle better one would expect.i'm thinking of starting with those and then if its too raunchy, adding a short spiral to the end before a down turned tip. I'll go 3.5 off the collector through the bends to 3" at the muffler.

Can you add a cross over tube? Said to be worth it for both noise and power. Next would be a call to Walker? They may have some great info.

So this is what I ended up doing. Took me a little while to get back into tig welding, haven't done anything for like 6 months. System is 3.5" all stainless with dynomax mufflers.

fitting and more fitting.

Made the tailpipe downturns, Welding it all up tomorrow.

They are nice well built mufflers and not too expensive. I have the oval ones. I have been running them for about 8 yrs along with a couple friends.

I like the Kooks polished stainless mufflers. Best looking and sounding muffs I have ever had on any of my street strip cars. They are at home at both places.

When it came down to it, the dynomax mufflers were the only thing in stock when I ordered. Even getting the 3.5" pipe was tough, most places were 4-6 weeks backordered. I got my hands on a length of pipe and it was made in Taiwan, had to wait for a second length, same brand of pipe and it was surprisingly made in Canada. Maybe the supply chain is starting to come home now.

You can buy 3.5 in pipe at most heavy truck part places.

I tried that, the straight pieces they had were Aluminized steel, and their stainless went straight jump from 3" to 4" with no half sizes. It was fun walking in around in their store though.

Nice slices of pie!

are there any dyno tests of these? Don't think they are in any of the Engine Masters shootouts.

We're trying to decide what to put on my brother's Charger, 600hp 493" but want it as quiet as he can without killing 40hp.

Tack welded up , will do the last of the welding marathon tonight or tomorrow.

The longest case muffler you can fit, straight through. You would be shocked at how quiet a 20 inch case Ultra Flo is compared to the little 14s.

I wound up running 3-1/2" slip-on collectors with little tabs to bolt to the header collector. Then I welded some 3-1/2" pipe from the slip-ons to a 45* bend. I added a 3-bolt flange before going into a Dr Gas X-Pipe. The X-Pipe is 3-1/2" in and 3" on the outlet. I ran the 3" pipe on the output side of the X-Pipe to a set of Ultra-Flows. I cut up the factory chrome exhaust tips that exited out through the rear valance panel of the 'Cuda and added 3" pipe adapter to the chrome tip. I exited the exhaust just before the back tires. I sent the whole system out to Jet-Hot for satin black coating. I've been happy with this setup with the exception that it's maybe a bit too quiet. I plan to reinstall the Flowmaster original 40's that I had on the 'Cuda back in the 90's. I added 1/2" quick pins that hold the tailpipe hangers to the 2 x 3 box tubing that goes from rocker panel to rocker panel in the floor just behind the front seats. When I go to the track, I slide out the quick pins and undo the 4 bolts so I can easily slide off the exhaust, drop to the ground and slide it under the trailer. I left some torque on the table because I didn't run collector extensions at the track. Engine Masters did an episode that showed pretty impressive gains by running header collector extensions. I'm getting ready to redo this setup since my new headers have 4" collectors. I'll use V-Band connectors on the header flange to exhaust system this time around. And I'll have to long transition from 4" to 3-1/2" to match the size of the X-Pipe inlet. There was a post on here about a month ago where a guy with a really nice Pro-Mod white Duster did a custom exhaust using oval stainless. It was a work of art. You should check that out for inspiration