ring and pinion ratio suggestion

That cam is about the same as a factory 340 cam, with some extra lift. So what you seem to be ending up with is a warmed up teener with a possibly ever so slightly, soggy bottom end with just a 9.4 compression ratio.(EDIT; Naw, I changed my mind, the Dcr comes in at about 7.8@155 psi. I don't see that as soggy at your weight and with a reasonable rear-gear.)The 2.92 low gear will help,as will the light chassis, and the H-pipe. IMO this cam will want a starter gear of around 10. I'm guessing 10/1 will be sufficient. That means a rear gear of about 3.42.
Since you offered options of 3.31 and 3.54, the final decision may have to be the hiway revs..
3.31s will cruise at 65=2670, 3.54s at 2860. Both with 27s. That is to say about 190rpm difference. I have cruised at both rpms and many others. With a good 3-pass muffler and full exhaust, this is no problem as to noise, just make sure the exhaust does not exit under the car.
This engine will be capable of great fuel mileage, and with the 9.4Scr, and about 7.8 Dcr, you should be able to run some pretty low-octane gas in it, at least on the hiway. To that end,when in doubt, err on the conservative side,3.31s in this case. With such a light chassis, you will want some bigger tires under there, to try and grab traction. If you can fit 28s in there, then you can run the 3.54s, for 65=2760rpm, right up the middle!
BTW
That's a real nice tranny; the splits are pretty even at right around 70%. What's that come from, and is there a bellhouse to bolt it right up to the engine?