Exhaust routing

[IndianaK5]

I've been searching the forum for a while trying to get as much info as I can, but I haven't been able to find anything directly related to my question.

I have a 72 K5 with a small block. I'm planning on running the stock ramhorns. It has an aftermarket intake, mild cam, and a 650 holley with vacuum secondaries. I had headers and duals running out the back, but I'm a little tired of the headers, plus the truck is a 4 spd. Getting the clutch linkage away from the headers and in alignment has been challenging.

I'm going for a reliable daily driver and relatively quiet. I've been thinking about going with a two into one setup, similar to factory with exit behind the driver's side rear tire. Any of you guys running a similar setup. Any advice on muffler size, tubing size, and exhaust routing? I do go off-road occasionally, but nothing aggressive. Just light summertime wheeling to a nice camping/swimming spot.

thanks
Zach

[budster]

My 72 has somthing similar to http://www.castheads.com/corvette_systems.php#manifolds with 2 1/2" pipe.

I'm not sure what mufflers are on it, I'll know when I lift body off. I've heard a lot of people like the flowmaster 40 series but I've read they are pretty noisy inside.


*Edit* Totally misread your post. The link to exhaust manifolds still might be appropriate if you want to spend the money, a little bit of hp gain and I dont have fitment issues with the clutch. Going with stock manifolds or the Brzezinskies would let you keep the dual exhaust unless you really want to get rid of it. I did a search on flowmaster and thats where I read the 40 series was a lil loud on the inside. I think I covered most of the stuff I misread. Good luck.

[IndianaK5]

budster,
great link. I'm thinking about getting rid of the duals, just want a reasonably quiet exhaust. I have duals on it right now, and its just too loud. It's fun to start it up and have my friends grin, but after the initial surprise, it's a bit of a headache. I'm pretty sure its the muffler to blame, but before I switched to duals, the truck was fairly quiet with a smaller muffler. Right now, when the engine is between 1,500 and 2 grand you can't hear because of the exhaust resonance. This is really where the motor spends most of it's time.

I'm also not sold on duals being the best for performance. They may be the best for the wide open throttle guys, but I'm living in a much different rpm range. I'm looking for good low and mid range grunt. I've got that granny gear and 3.73, and I don't really do much freeway driving. I think a nice two into one just before the muffler, with a decent sized muffler would flow adequately and suppress most of the noise.

I was really concerned with unequal length primaries, but after looking at the link, I don't think its going to be a real problem. Definitely going to try to go with some sort of collector just before the muffler. I saw that some of you guys are running 2 1/2 corvette style ramhorns, do any of you run the factory a/c brackets with the aftermarket rams?

[vtblazer]

Originally Posted by IndianaK5

budster,
great link. I'm thinking about getting rid of the duals, just want a reasonably quiet exhaust.

Your noise isn't a function of running dual exhaust, it's due to 'muffler type' - 'muffler position' and how/where the pipes exit the vehicle.

Having a cross over, 'H' or 'X' pipe installed in the system helps a lot to tone em down too.

I installed a set of vette 2.5" rams with flowmasters 40's, a cross over had the pipes exit out near the rear bumper on the sides and the blazer was completely drivable at all speeds, quiet even.

If you have the room, flowmaster 50's sound really nice, they rumble but with a small block their almost 'to' quiet.

Research mufflers, there's a ton of different option's out there.

Pics from one of my recent blazer, this set up was pretty quiet too.