Long Tube Headers - '66 289 (347ci)

blkfrd said:

Wait a minute...your concerned about loudness and your considering spin tech race mufflers?

I second Dougs Tri-ys for clearance, quality and performance. They have a manual trans version and an auto trans version tri-y

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lol, I didn't even notice the loud part. I have the spintech pro streets on mine and if your worried about being too loud you may want to get a lvl down in their series of mufflers. I'm at 14-1 so might be a tad louder cause of compression and cam, but still if thats even a concern with you, go to the street mufflers with x-pipe. (2 1/2")

You got a very good set of heads. Do not impede their flow if you want to make power.

Use at least the Demon 650. My vacuum secondary Speed Demon 650 has propelled my na 347 coupe into the 11's numerous times.

I also run Hooker Comp 1 5/8" headers and like coolblue stated, they hang a little low but I have never hit them on anything. With your cams intended range I would stick with the 1 5/8" primarys.

Your cam is the XE268H. I ran it on an old low compression 302 with the wrong valvesprings, 3.55 gears, c4, and 215 drag radials to 13.2's all day long. With the 347 I would bump it up to the XE274H (230/236). It is the cam that got my 347 into the 11's. The rpm range of those cams listed is for a 302 engine. More cubes will lower the rpm range.

Behind the headers I run a 2 1/2" h pipe and Magnaflow mufflers. Works and sounds great. If I had to do it over I would go with an x pipe though. Seems like it would keep the gasses flowing faster.

Good luck!