So, I'm just wondering, but, would it not be easier ,cheaper and just as effective to run hiway gears and install a slightly looser TC or an A998/999 with a 2.74 low gear. IMO, for your stated use,it would be a natural.
I agree that 2200@65 is really nice.
With 275/60-15s (28s) tires, this is 2.82s@zero-slip. The closest could be either 2.94s or, 2.76s which you might already have.
(With 225/70-14s these are 26.4 tall so 2.76s are the go-to.)
The 2.74 lowgear with 11.8% more TM,will help get you going , seeming like the next size bigger rear gear.
But the clincher, to get back some take-off power,would be a 2400 or a 2800 TC, and then a good tune in the engine to take advantage if that newly released extra torque.This might add 20 or probably 30 ftlbs off the line, seeming again like 1 or 2 sizes bigger rear gear.
I'm just thinking about what you said. At zeroslip (loc-up TC);
65=2284 with 2.76/25.5s, and,
65=2293 with 2.94/28s, and
65=2153 with 2.76/28s.
I ran that combo; A999 with a 2800 and 2.76s and 27" tires for a couple of winters in my 68 Barracuda. It was a great cruiser. I also installed a semi-manual shift kit in that tranny so I could shift up/down at any speed or rpm. And headers were already in the car. And I installed a small-port intake, a small TQ and 5500rpm valve-springs. You might be thinking, that's not what you want. But check this out;
I used to floor it from a stop and get her into 3rd as quick as possible,then let the TQ moan all the way to 65mph. If you've never heard a TQ-moan for like 17 seconds, you'll be in for a treat,lol. Well ok 17 is an exaggeration.
Those 1.5" TQ primaries are great for mileage,and 2233rpm@65 (zero-slip) with 27s was great.
The A998/999 requires no extra work to install.And they are cheap to buy/cheap to build. The TC,if you choose to purchase one, will be your major expense.My 2800 did not slip all that much at 65. Until I slammed the pedal down,lol. Then the tranny kicked down and the TC buzzed up and the Rs climbed to over 3400 and I could pass anything.
BTW, the A500 has these same ratios; 2.74-1.54-1.00, but includes the .69OD.
But I get the attraction,The A500 will allow 3.91s to get nearly the same cruise rpm as 2.76s yet have 58% more first gear TM! That's a lot. I ran my 318 with 4.30s for one winter. That was plus 74% compared to 2.45x2.76. And it was awesome with that 2800.Too much for a winter motor.That was 11.78 starter gear;crazy in winter. Pretty much useless.I never ran that 4.30 behind her again,lol.Actually I did. The previous winter I ran those 4.30s with an A833O/D and a GVOD behind it but that's another story,lol