Thinking of going back to exhaust manifolds...

Here's my opinion

Manifolds are not going to get rid of drone they will probly kill off 30 h/p above 3k

Running tailpipes will cut it in half and probly won't hurt power much if any

Adding a pair of resonators in and near the end of the tail pipes will knock it down more

Getting rid of the flowmasters will help too and gain power more then likely

Really the Stock manifolds suck for a turbo build but will make enough power to split the crappy 302 blocks the problem is the doughnut gaskets burning out and makes it nessacery to deal with not being able to use the stock oil filter location.

 

Wholy crap i just spent a hour going through exhaust calculations! So far it says he needs 5'' stacks!! Must have put a decimal some where wrong..Anyway i really dont think 2.25-2.5 exhaust is going to make a night and day difference but this could turn into a Holley vs Edelbrock debate very easily.I'm liking the extra hanger ideas he could be experiencing more vibration then resonation

 

I had a 89 mustang 5.0 and the previous owner had put a set of three chamber flowmaster muflers on it. It had 2.5 inch exhaust and the pipes went all of the way out the back and the resonance at hyway speeds was so bad that I ended up selling the car. I personally wouldn't put flowmasters on anything. I have a magnaflow mufler on my explorer and don't have any resonance problems at all. I have never had that problem with regular glass packs either. I am planning on putting a 302 in my mave this winter and will more that likely use glass packs or maybe magnaflows with a cross over pipe. I will use either stock manifolds or short headers to avoid shift linkage problems. Just my .25 worth. Good luck.

 

I had a thought. weld a bar to a pair of Muffler clamps and mount it temporarily to the pipes. move it around to see any changes. I like Gene's reasoning. you may need to change the position of the clamp as the distance between the pipes varies so don't get too carried away welding them. this is just a test. if you find it makes a differeence, then make something permenant

 

That's a good idea. I can see a problem if the pipes are not evenly spaced but at least the welding isn't on the actual pipes. Hey, might be able to find a good note to listen to

 

I still say you need to run the pipes PAST the rear axle. Mine had that drone until I had my pipes run out the back. Hooker 6901's, 2.25 pipes, Flowtech Red Hots glasspacks. It quieted the car down at idle a little bit, lost the drone, but will still sound off when you mash the loud pedal.

I'd bet the pickup has some kind of tailpipes, so it will not drone like a shorty pipe would. If you don't want to run them all the way out the back, consider going over the axle and dumping them between the spring and body, pointed down at a angle to the outside.

You like to experiment, so buy some cheapie flexable exhaust tubing, cut and bend, and try it. If it works, then you can go to a muffler shop and get real pipes bent up. If it doesn't, your only out the costs of the flex pipe and hangers...

 

I am sure glad we have this all straightened out!

And yes, I DO want to be able to adjust the bailing wire for various tones! I have spent the entire day trying to figure out a way to slide them forward and back while driving so I can adjust the drone AND tone!!!

Regardless of all the other drone banter, I think I got my answer regarding the original question, somewhere in there. Stick with the headers...