There are a well mapped, but very vast, array of C4 converters around.
You can grab the 8" after market items from TCI or suchlike, and they can go to over 3400 rpm on a litle six.
They look darn expensive until you understand that
a) they raid existing stock converters, and rework them with special furnace brazed bits.
b) most stall figures are estimates only. The better hi stall converter companies bench test on machines, and can rate the stall ratio ( usaully 1.8 :1 to 3.0:1) and the actual stall speed (rpm of the recomemended combination at the point at which full torque transfer happens, usually 1650 rpm on a stock low power V8, or 2350 rpm on the CJ/SCJ/SC/HO versions of Fords V6's and V8's. The sixes have different stall ratios, but Ford use the same 252 or 256 degree cam on all I6's and base V8's, and tend to use the same stall rating.
Please note, the stall ratio of a 1650 rpm V8 converter on a stock 200 I6 is likely to be less than 1300 rpm. If a 5.0 converter is placed on a 250 I6, it will have the same stall ratio becasue large sixes produce a great deal of low end torque compared to a V8 A stall converter with 2300 rpm on a 2.0 would be 1800 rpm or less on an I6 200 cube. Jack Collins said a torque converter reacts to how much torque it 'sees'. Lots of low end torque, high stall, Little low-end torque, low stall. That's why the Chev guys used Vega converters on there cammed up SBC + THM 200/350 racers.
Pinto converters are now very rare as they were only used on early 2.0 Pintos from 1971 to 1974. Accoring to litrature on the C3, Borg Warner 35, and form they guy who used to make C4 gearboxes for drag racing Pintos in the late 70's, early 80's, they were a fairly hi-stall ratio of about 2.1:1.
On a 2.0 Pinto, stall is around 2300 rpm or so. The C4 was a German market item for the V6 Capri and Eurpoean V6 Granada, so it was set up loose for engines with next to no bottom end torque. The four cylinder Pinto engines came from either Britian or Germany, and used the stock V6 stall ratio. I think the figure was 1.9:1 for the little 2.0 V6, which had very little low-end torque.
On a stock 200 six, the Pinto C4 would be about 1800 rpm or less.
On a cammed up 200 six, the Pinto C4 could be 2000 to 2300 rpm.
Stock 200, its about 1600 rpm for most of the 64 onwards C4's.
The Pinto converter needs to be welded up to the four lug, 9.25 or 9.375 spacing, and then diligently checked against the stock 200 C4 converter. Then cleaned, flushed. It needs a dial gage check on the run out using a dummy C4 with the same input sahft tang as the transmission you use.
It then needs yo be fitted. If it engages incorrectly, then it'll take the transmission out, and all you savings will amount to nothing. .
