383 single to dual exhaust conversion

[qkcuda]

My 66 Charger was a 361 two barrel. It uses the low performance manifolds and the previous owner had a 2 1/4 system bent up. Seems like they cut the Y pipe and used the stubs and sleeved the new pipe over it. It has huge mufflers and is very quiet.

 

[DaveyG]

Are you keeping the two bbl, low performance manifolds? or swithching to the correct and matching hi-pi exhaust manifolds. I think if you duals on the low-po manifolds, it will need to be custom bent.

Tough question.
This car came stock with 2bbl, single exhaust and I still need to find the manifolds numbers, but I'm sure it's all original. In fact it had drum brakes on the front end. Go figure. Living in the hills of San Francisco at the time I had to convert to discs. That's the only change I made. Opening up the exhaust was stressed by my hot rod brother as an important minimal improvement. I don't think upgrading manifolds is in the cards. That would lead to many more "improvements" that I'm sure would make it a runner, but I'd like to keep it simple and stock for now. It looks like Magna Flow stocks the manifold connector pipes (https://www.magnaflow.com/collections/1969-dodge-charger-exhaust-systems). Please let me know if you think it will not bolt up. Thanks for your input!

 

[BSB67]

I don't think it will bolt up.

 

[hunt2elk]

If you want it to look like the factory duals, Accurate would be your best bet. I have used them in the past with good results. Remember you will also need to get a drivers side hanger bracket as your car wouldn't have come with it.

 

[WileE]

Thanks Oregon! That's the kind of info I've been looking for. What benefit is the H-crossover compared to no crossover?

Won't go into a wall of technical text, but simply.. acts as a balance for exhaust excavation, backpressure, and resonance. It's... good. Single exhaust chargers are (were) actually common, since all 383-2v and 318's had it. I'd get the Accurate system if it were my car.

 

[WileE]

If you want it to look like the factory duals, Accurate would be your best bet. I have used them in the past with good results. Remember you will also need to get a drivers side hanger bracket as your car wouldn't have come with it.

Yep. Kickup bracket as well as the tailpipe hanger on the end.

 

[G.V.Charger]

Been a while since I replaced an exhaust system, thinking, 15 or 16 years ago...Stainless..and I will probably get another 5 to 10 out of it. So, you only get what you pay for!!!
When I sent the 67 in, the biggest concern I had, was. did the shop owner, still possess the cards, yeah, the old angle cards muffler shops had to aid them in reproducing the right bends and angles. Had the shop do the job, however, I was still a little unhappy about the alignment of the pipes left and right of the drive shaft, passenger side a little lower? Always thought the mechanic messed it up... apparently, he was right, and the measurements were to the tee.
I was looking at the exhaust system on Dave Walden's OE gold Challenger and figured out the cards were correct.
Checked the magna flow price's, nothing special, if you have to install it. I would check some local shops for some numbers. I would rather leave that work for the shop, in case of leaks and rattle's.

 

[DaveyG]

Won't go into a wall of technical text, but simply.. acts as a balance for exhaust excavation, backpressure, and resonance. It's... good. Single exhaust chargers are (were) actually common, since all 383-2v and 318's had it. I'd get the Accurate system if it were my car.

I'll be calling Accurate on Monday for more info on the manifold connector pipes. Thanks!

 

[DaveyG]

Are you keeping the two bbl, low performance manifolds? or swithching to the correct and matching hi-pi exhaust manifolds. I think if you duals on the low-po manifolds, it will need to be custom bent.

I've been reading over all the posts and thinking twice about performance. Got any suggestions for 4bbl and exhaust manifolds (afraid headers would get too loud). Would a 4bbl also mean changing the intake manifold?

 

[BSB67]

Size of the exhaust pipes and type of mufflers will have a bigger inpact on loudness than headers verses manifolds.

Yes, a 4bbl intake manifold is needed to install a 4 bbl carburetor.

 

[DaveyG]

I measured the existing exhaust pipes finding 1-3/4" head pipes joining into 2-1/4" to the single muffler. The muffler measures 10"x 20" with a 3" inlet and 2-1/4" outlet. The tailpipe is 2". Someone installed the muffler for me long ago and filled the in/out with lots of welding to match the pipes. I mention all this because it brings up another question: Do the diminishing diameters serve a purpose such as required back pressure?

 

[DaveyG]

I called Accurate Exhaust and found they can make a bolt up dual system conversion including the head pipes and flanges. 2-1/4" throughout including 20" factory mufflers, and over axle turned down pipes.

Thanks all for your thoughts and advice!