"drop in" small block

Thinking outside the box:
>Your current combo,the A904/3.23,has ratios of 2.45-1.45-1.00,and with the 3.23s,has road gears of 7.91-4.68-3.23
You might consider the A999automatic with its ratios of 2.74-1.54-1.00, and 3.55s, and a 2800 TC.This combo will get roadgears of 9.73-5.47-3.55
That is 23% more torque multiplication in first,16.9% more in second, and 9.9% more in direct. The A999 has a lock-up convertor making the cruise rpms a no slip situation.
>Now, the first gear at plus 23% ,will make your 273 feel like it just grew 63 cubes. And second gear, at plus 13.9%, will make your 273 feel like it just grew 46 cubes, and direct like plus 27 cubes.
And we haven't even factored in the TC yet.
Outshifting at 5000, first will get you about 37 mph. Second will be about 66mph, and third about 102mph. 65 =3046. All calcs are with 25.5 tires, and 5% slip.
Factor in a 2800TC and this will be rapid transit.
Time spent? Less than one day with just swaps.
Cost ? probably less than $400 for cores, plus the gears,TC, and rebuild kits
Total? I'm guessing $1500
Now, go back;
>The 273 if operating at about 1.06 ftlbs per cid is gonna put out about 290ftlbs@3500 rpm. With the new gears, this will be putting down 2821ftlbs@26mph into the rear axles.
A stock teener by contrast also putting out 1.05 ftlbs/ cid, will muster 334ftlbs@2800 ish rpm. With the current gears, this will be 2643 ftlbs@27mph into the rear axles. So the 273 wins with 6.7% more torque into the rear axles at 26.5ish mph.
And we haven't even factored in the TC yet.
>Lets look at second gear. First the 273. At 3500rpm she will be putting down 1585 ftlbs@46mph into the rear axles. And the teener at 2800 will be putting down 1564ftlbs@43mph. Now they are neck an neck.
>Third is past the speed limit, so who cares. But if you really want to know; the 273 will be doing 1029ftlbs@71mph, the teener;1079@63mph.So now the 273 is finally showing its smallerness,and falling behind.

>Now lets look at the TCs
The 318 probably stalls at about 1700. If I guess it makes .4ftlbs/cid here,then it will put 134x2.45x3.23=1060ftlbs into the rear axles. The 273 with a 2800TC might be making,guessing again; .7ftlbs/cid, then it will be planting 203x2.74x3.55=1975ftlbs. This is an increase of 86%. This is HUGE! Like slapping a turbo on huge.
>And Finally, the cruise rpm. Current cruise might be 2771rpm@65.
The 273 with 3.55s might be 3046 in loc-up mode. This is where the 273 loses 9.9%. But since it is 15.2% smaller than a 318, there is a strong possibility that it will still make considerably better mileage than the teener.
And we haven't even talked about road horsepower yet!
>If you want to save a ton of time and expense,and don't need the cruise Rs to be low, go straight to 4.30s or better, and leave both the tranny and the TC alone. 4.30s will get you a 2-gear blast to 65 mph, ending at 5600rpm. Let that sink in... 4.30s have a starter gear of 10.54. At .4ftlbs/cid, at 1700 stall, the 273 might be delivering 1151ftlbs into the rear axles,being plus 8.6% more than the teeners 1060.. So, for the cost of the 4.30s and the install, you have made a rocket of the ol' 273 car.Dad already has the 8.75 in there so this is a natural, and it's reverseable! Just get yourself another pumpkin, any pumpkin. Plus a good working LSD.
Your cost?IDK, maybe $800ish ready to drop in. I just sold mine for $450 canadian,so deals are out there.
Your time? an hour and a half or so.
Just don't think of cruising the hiway with it unless you have lotsa time cuz 50=2840ish rpm. But man will it be quick to 65. You will need a traction aid.