I recently purchased a set of Thorley headers For my 69 F-100
390FE. They are equal length 1-7/8" primaries,4 into 1, 3/8 flange, and 2-1/2" collector. The rest of my exhaust is 2-1/2" through twin turbos out the back with a crossover. The cam will be a solid grind clay smith 292 advertised, 240 @ .050, 108 lobe center .570 lift. 2000 to 6000 operating range with a c-6.
Did I make a bo-bo with the 2-1/2" collector? I figured that
if I had a 3" collector and was necking down to 2-1/2" pipes
I would be losing velocity and flow, but now I am stuck with 2-1/2" pipes.
Also, how about this:
IMHO I hear a lot of pickups that sound like a noise maker is attached (glass packs or somthing) but can't seem to accelerate very well. Reminds me of when I was a kid and would put a piece of cardboard in the spokes of my bike with a clothespin. I would rather be in front of these people ( where I always have been} and don't hear the noise. Course they never accept getting beat
and roar past me at the next light popping my eardrums and picking up there speeding ticket a half mile down. Well I thought about those warrior mufflers that you can un cork for fri night drags but how do they sound corked?
Also anyone ever wye pipes with covers out the side, and does this cause turbulance when capped for the street?

 

[font size="1" color="#FF0000"]LAST EDITED ON 05-Aug-01 AT 10:44 PM (EST)[/font][p]I have the flowtech headers for my 360 and the flowtech warlock mufflers which have the "cork" in them. My exaust is a 3" with a crossover. I love the way it sounds. It isn't extremely loud but does give a good rumble. Uncorked it is like open headers. Also the cork creates a smooth path for the airflow through the muffler when installed. They sound nothing like glass packs. I would say they are a little quieter than 2 chamber flowmasters but not much. My 360 also is a stock .030 over VERY poorly rebuilt motor. When I make it a 390 with 400+ HP it might be a tad louder.

 

 

Thanks Rat Smoker.
I will try a set of them.
I had my 390 rebuilt locally and while they did a good job
they didn't know anything about the oiling mods for the FE's.
The machinist is now one of my best friends and knows a lot about
chevys. Lol.
He has helped me in a lot of other ways and my next build will
be a good and low cost.
He is selling me a 390 block for $75.