I finally have my wagon back on the road! I had my rear cooler fitting snap off in the trans, had to concoct a goofy air cleaner drop base/spacer/filter setup to clear my hood with my goofy spacers for my Quadrajet, etc etc blah blah. My ridiculous bypass hose setup doesn't leak so everything else is gravy.

So, I haven't gone too hard on the car yet due to a less-than-ideal throttle cable vs primary shaft angle situation (waiting on one of Rick's brackets) but it really blats like a mean mofo in the bottom of the rev range under a moderate-but-normalish-driving foot.

Here's what it sounds like on moderate acceleration :
http://vocaroo.com/i/s1x2OUWUhRu1

Why am I getting this load-dependent ruckus in the lower RPM range now? Carb/fueling, timing, engine begging for headers?

The exhaust is duals off stock manifolds with no H pipe, mufflers are Flowmasters of some kind (presumably 40s)

Add H-pipe, ashcan Flowmasters.

R.

never thought flowmasters sounded good

Me neither, they came with the car but never sounded like this with my old motor, just usual "doog doog doog" resonating in a garbage can kind of noise. After I put some more miles on this new setup I'm switching to long tubes/H pipe/Jones packed mufflers.

I did a magnum swap on my jeep. Stock 5.2 mag with EFI, stock manifolds with 2.25" duals that dump in front of the axle through thrush turbo mufflers. They are quiet, too quiet, even with the doors and roof off!