exhaust question

[99xcss4]

I could be wrong but I think 305 vortecs were single all the way back and 350 vortecs got duals to the muffler and it came out as a single. the truck has a 305 for now. pans are 350 or a stroker. so it has one rear o2 and when my friend got the truck the tail pipe and the muffler was cut off only the mid pipe was left and the cat had been gutted. we had planed to get the pcm tuned and get rid of all the emissions codes. even though this is ultimately a singe exhaust my question from post #4 is would it be worth it to run duals to the muffler or just stay a single pipe

 

[PlayingWithTBI]

We're not in synch, I was replying when you just posted this, but anyway look at a straight flow muffler and/or 2 with dual exhaust plus, if you can afford it, an X-pipe to help scavenging.

 

[kennythewelder]

I could be wrong but I think 305 vortecs were single all the way back and 350 vortecs got duals to the muffler and it came out as a single. the truck has a 305 for now. pans are 350 or a stroker. so it has one rear o2 and when my friend got the truck the tail pipe and the muffler was cut off only the mid pipe was left and the cat had been gutted. we had planed to get the pcm tuned and get rid of all the emissions codes. even though this is ultimately a singe exhaust my question from post #4 is would it be worth it to run duals to the muffler or just stay a single pipe

You could be rite about the 305, IDK. I swore off 305s after I got rid of my 79 long bed. I found out why they call them 3 oh slow. Mine had a cam, and several other mods. MPGs sucked, and it was still slow as hell.

 

[99xcss4]

Just keep in mind dual 2.25" pipes flow about the same as a single 3"


^^^X2 - here's a better muffler I put in to replace my 3" - 3 chamber muffler, great sound with no drone (gained some HP too). Plus it's made in the good 'ol US of A!!!

https://www.amazon.com/gp/product/B0060EI9XK/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

he all ready has it on so it is a bit late for that. I know you can gain from a x pipe that is why I was thinking duals to the muffler but since it is going to be a single exit would the gains it would give still be thers

 

[PlayingWithTBI]

I know you can gain from a x pipe that is why I was thinking duals to the muffler but since it is going to be a single exit would the gains it would give still be thers

Probably not for a 305, just stick with a mandrel bent 2-1/4" to 3" Y pipe and 3" the rest of the way back.

 

[kennythewelder]

I guess I should have read the whole thread. Info is always important. I will throw this out there FWIW. A Camaro and Trans Am and even a Vette all run or have run a Y pipe for the scavenge effect. On my 97, the O E exhaust was duals into 1 muffler then a larger single exhaust coming out of that muffler. Not sure what sizes the pipes were though. Again, just more food for thought.

 

[kennythewelder]

Probably not for a 305, just stick with a mandrel bent 2-1/4" to 3" Y pipe and 3" the rest of the way back.

By the way, I did recognize that new avatar. Had to look at the name. I do recognize those valve covers though Ha Ha.

 

[PlayingWithTBI]

but anyway look at a straight flow muffler and/or 2 with dual exhaust plus, if you can afford it, an X-pipe to help scavenging.

My bad - I misspoke an X-pipe is good for higher revs, which your 305 will probably never see. An H-pipe gives you better low end torque. Hell, my 69 Plymouth GTX 440 came out of the factory with 2-1/2" duals and an H-pipe. I had no problems adding long tube headers (among other stuff) and running the OE pipes back (except I put in 9" T-Bird resonators instead of the mufflers) putting out a lot more than 385HP factory output, LOL!

 

[99xcss4]

Probably not for a 305, just stick with a mandrel bent 2-1/4" to 3" Y pipe and 3" the rest of the way back.

yes agree I am thinking a bit a head and not to go too far off track it was not to hard to make him understand that boat anchor of an engine has to go the truck has 35s 6 lift and is on its second 4l60e. even though the dual y pipe is a little cheaper at 150 and the single is 166 why this is I have no idea a single would not hold a 350 or stroker back too much and it would most likely be simpler and maybe be a bit lighter.

 

[PlayingWithTBI]

By the way, I did recognize that new avatar. Had to look at the name. I do recognize those valve covers though Ha Ha.

Yeah, I got bored the other day and decided to look through some of my pics from my build.