727 torque converter questions....

1967 to 1977 318-383-400 with a steel crank used a 12" converter no weights.
1972-1973 440 cast crank 12" with 2 weights
1972-1976 400 cast crank 12" with 2 weights
360 up to 1976 12" with 2 weights
The weights are welded on the back (mounting side) of the converter. All 12" converters used a narrow ring gear (about 1/2").

1972-1976 6cyl and 318 11" no weights wide ring gear (about 1").

Hemi and 340 had their own converters and at the shop I used to work at, custom builds only (cores are almost impossible to find for the hemi), and the 340 converter isn't all that common, but;
1969-73 340, 11" no weights, wide ring gear.
1973-1976 400-440 11", wide ring gear 2 weights.


On a stock 383, you might find that 25-2800 stall a bit loose. A lot depends on tire size and rear axle ratio. Lots to think about before you put a high stall in.
Looser ain't necessarily better.