so I'm inheriting some headers for my /6 from my brother...the are the hooker style headers you can find online. I'm running a 2bbl and an HEI...I plan in the long run to do some head work and install a cam....That being said i want to stick with a single pipe with option to run open...What is the best exhaust plan to run...I've heard differing options on this. The collectors are 2.5" and I have 2.5"x3ft tubes off to run this.... but I don't want to have to redo the exhaust with my future upgrades. Differing opinions come in where friends have said I don't want to go too big b/c the gases will cool....Especially since I was thinking of the 2x2.5" "Y"-->3"pipe-->3"cutout-->Flowmaster outlaw 15430--> 3" dump.....OR 2x2.5"-->3" Pipe-->3" cutout-->Summit SUM638230-->3"-2.5" reducer--> 2.5" dump....The only other option i came up with on my own (being new to this) was 2x2.5" pipes w/"H" crossover and 2.5" cutout from one of the pipes---> to Cherry Bomb 7467--> to single 2.5" dump.........DD, Uncle Dan, what is the best way to go for the setup I have and future upgrades, single pipe w/ open option? Again i don't want to redo exhaust with my future upgrades....Thanks -Mike

oh, and This is for a 70' Dart Custom

I personally would highly recommend steering clear of 3" pipe, its ok on V8 applications because they flow more exhaust, but our little slants just don't flow as much. I think the general consensus on this board is either 2.25" with a 2" tailpipe, or a full 2.25" or 2.5" down to a 2.25" or 2" for a tail pipe, the reason being that it takes out the drone you get from bigger pipe and also as gasses cool off as they get to the rear of the exhaust system there isn't as big of a need for a larger diameter pipe. I run a 2.25" pipe from the manifold, to a 24" glass pack between the backseat and front seat and then a 90* turn and out the side and I only get drone for about 5 miles per hour, about 40-45 miles an hour is the "drone zone" but other than that no complaints.

If it was my car I would do true duals with 2.5" until the transmission cross member, then step down to 2.25" and a H or X pipe, then the cut outs, then muffler of your choice and then either out the sides with 2.25" or out the back with a 2" over the rear axle.

My .02 cents,
Seth

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Annabelle: 1970 Dodge Dart Hardtop
1991 Nissan 240sx (sileighty) Lots of mods
1974 Dodge Dart *Wrecked*

Thanks Seth!!!

For all but really wild Slants, I have found great success with 2X 2" off the headers to a single 2.5" right at, or just behind, the trans X member. I use a Flowmaster Y pipe with 2X2" inputs and 2.5" output, then full single 2.5" out the back. DO NOT let the exh shop make you a Y pipe, because it will almost certainly suck - been there...

Lou

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Home of Slant6-powered fun machines since 1988

I am of the exact opposite opinion, run the biggest pipe you can afford. A 225 is half a 454, and nobody would even consider running a 2" exhaust system on one bank of that engine.

I would run the 2 1/2" pipes into a Flowmaster Y and then a single 2 1/2" pipe out the back.

In my case I am running 2 1/8" head pipes off a set of Dutras into a Flowmaster Y and a single 2 1/2" pipe to the rear axle where it dumps on the ground. The only reason for the 2 1/8" pipes is that 2 1/4" doesn't quite fit between the bellcrank, steering linkage and the torsion bar on my '65 Dart.

I first ran this setup on my basically stock 225 with an Autolite 2100. After it was installed, I had to increase the jet size by four steps to handle the extra air flow thru the engine.

Sounds like our opinions are pretty darn close to me...

Lou

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Home of Slant6-powered fun machines since 1988

i have to pull a head from the yard since my manifold bolts are in such bad shape. That being said, I've decided to go through it....shaving maybe .1" but keeping stock valves and a stock cam. I've had friends stating they'd go with a "Max Wedge"-style exhaust...Running the 2x2.5" pipes (off the headers) w/ 2x2.5" x3' long collectors, into a Large pipe, keeping option to open large but keeping it capped...off this pipe run 2.5" into a 2.5" muffler...so to leave option to be large and loud while headers are open but creating the necessary pressure and heat while closed...what do you think? BTW thanks for all the input from everyone!!!