3:55 gears to 323 gears
2:5 TTI exhaust Dynomax super turbo mufflers at 60 turning 2900 rpms it seems like it’s turning more and it’s loud lol.
At one time, in my 360/4gear/3.55s/68 Barracuda, I ran the Mopar 292/.508cam (.543 with 1.6 arms) @ 11.3 Scr.The car had a TTI dual Full-length 3" system also with Dynomax muffs. But I bought mine with turndowns that I ran to just under the bumper : and yeah it was a lil loud. No drone tho.
The math says 2870rpm@65mph, so you are spot-on. . I drove 56mph@2470 (3.55s)on short hops, but wore earplugs on trips over 20 minutes. I tried 3.23s but the cam did not like those.
I sold that big Purple as fast as I could. It just wasn't For me.
The next cam, a 270/.538, in at 10.70Scr now, was no quieter.
The final cam, a 276/.549, in at 10.95 now, is also no quieter.
In the end I bought a GVod which brought the Cruise-Rs down to 2240. It is amazing how much quieter the exhaust is. I threw the earplugs away.
As to fuel economy, it's been written that for every 1% decrease in cruise rpm, you will increase your fuel economy by half a %. So from 3.55s to 3.23s should be good for ~5%. But there is a limit. If your rpm gets down into reversion, then your economy will turd,fast.
You can find your minimum cruising rpm by just reving the engine up in Neutral and observing the manifold vacuum. The lowest rpm with the highest vacuum is it. When you find it, pull in some timing until the Rpm peaks. Then back up the rpm a few hundred, and slowly run it up again until the vacuum peaks, again; There it is. That is your minimum best cruise rpm and timing for it.. On the road, you may find that the engine is ok or even likes just a lil less timing than it did on the in-Neutral test.
Most guys are 15 to 20, or more, degrees shy, of optimum cruise timing. The sound and loudness of the exhaust, will mellow out, as the fire no longer burns in the pipes.
BTW
if that 11/1 engine of yours is aluminum headed, like mine;
I found a 223* cam waaaaay more fun, and it got 4cylinder type fuel-economy with an overdrive. The next bigger cam (a 230*) had a bit more topend power, but traded away a bunch of low-rpm torque to get it; and the fuel-economy was gone. IMO it was a bad trade. I solved the softness with a 3.09 gearset from the Commando box. I worked on the fuel-economy for 10 years but never could touch what the 223* cam had got. Both with same gears.
The reason I mention this is because that big cam of yours will not like 3.23s much, never mind less. Whereas my 223* cam liked anything, even down to 2.76s and as a100% streeter the 223cam was just as potent in the first two gears;
and 3.55s go to 82mph @7000,in second gear,
so IDK what more I could ask for,lol.
I have never missed that 292/509.
