IIRC the open chamber Eddies are 65cc, as compared to 70/72 for the 340 heads, and that should be good for a half a point on a nominal 8/1 engine.
From the several factory-stock,hi-compression 340s I have owned over the decades, I would never brag on their bottom ends with the factory 268 cams. So IMO the 8/1 engines would only be worse.
Couple that with a late-closing intake of a performance cam, and I can certainly imagine the sub-2500rpm area being soft.
But, you have a clutch, just like me, so off the line, you should still be able to lay tracks. And once the tires are spinning, it's just a matter of keeping the rpms high enough to continue laying 'em.
If your engine cannot do it with a clutch, then I doubt the automatic will be any different. And when she hits second, it will only get worse, because second gear with an auto, is about like third with a manual, the ratios being 1.45 for the auto and 1.40 for the manual.
But; even if the tune is right on;
if you are trying to lay rubber with the engine married to the tires, as in no clutch-slip, with 3.23s and 28" tires, that is not gonna happen , because the Rs are just way below where the power is, until maybe 3500rpm@34 mph, and by that time the car just accelerates. You can't get to 3500 before that, unless you toe the clutch. I mean, that's what it's there for.
And suppose you install 3.91s; now, 3500rpm will be 28mph, and you are still gonna have to slip the clutch out,or shock it into spinning the tires.
Here's the deal;
suppose your 340 makes 300 ftlbs at 3600rpm, at WOT/both barrels open and with full power-timing, which is 205hp. I mean just suppose.
By the time this gets to the ROAD, this is 205 x2.66 x3.23 x24/28= 1510 ftlbs. If you are driving at 34 mph, according to the gearing, then you will never break those 275s loose; 1510 is just not enough.
If, at 34 mph, you slip the clutch out to 5000rpm, and have 320hp there, that would be 336ftlbs, and by the math, this translates to 2475 ftlbs. And that, will certainly fry the tires.
If you want to fry the tires from a footstomp, you will need lotsa more footpounds. You can get it with a bigger engine, skinnier tires, less-sticky tires,more than 2.66 x3.23 gearing, or lots more cylinder pressure.
To that end, alloy heads are known to be detonation free at up to 185 psi on junk gas, and some FABO members are running up to 200 psi still on pump gas, with a tight-Q design.
Off the line, the TC will punch the Torque Multiplication up, but if the engine has a soft bottom-end, it could very quickly give that up.
The automatic trans once stall is achieved will make your combo feel about 10% bigger than it now does, by the way the TC works. So, your 3.23s will perform like 3.55s. But you will lose the ability to drop the hammer at 5000rpm,lol.
