Torque Converter Question

[NickJ]

Evening all,
  I need some advice. My Charger came with no drivetrain and I'm currently piecing one together. I found a 383 out of a 68 Charger (score!) and it came with an 11 3/4 flexplate. I then found a 727 out of a 68 imperial that had a high stall converter. Takes a 10 3/4 flexplate and also has a wide ring gear. I'm trying to pick a torque converter and Monster is asking whether I want a narrow (1/2") or wide (1") ring gear. I'm not sure whether I should copy what the transmission came with or what the engine would have come with. Does it matter? Any advise would be greatly appreciated. Thanks!

[John_Kunkel]

Converter selection depends on some other factors. Will the engine be HP or standard performance? What will the axle ratio be?

If the engine will be standard performance with a low numeric ratio rear end, the 11 3/4" (narrow ring gear) would be a better choice.

[Kern Dog]

I had a 1978 Trail Duster, original 440 and the transmission had been replaced before I bought it, It had 32" tires and 3.21 gears. The transmission shop put a 10 3/4" converter in it and the truck was a slug. It was s-l-o-w. The transmission slipped too much due to the converter size and tall axle gearing.
Conversely, my 75 Power Wagon 440 has an 11 3/4" converter and 4.10 gears. It is snappy and performs well.\
A stock engine does not need, nor will it benefit from a higher stall converter.
Maybe your high stall from that Imperial was another mistake made by a transmission shop. Imperials did not have high performance engines, their engines were tuned for low to midrange power.
Trucks and vans are a great source for these 11 3/4" converters. One from a small block 727 will still work as long as it is NOT a lockup type converter.

[NickJ]

Thanks for the responses guys. I ended up not using the Imperial transmission. We got it opened up and the internals were just gone. More rust than metal. Ended up rebuilding a good 727 core out of a 73 D100. Sat down with my transmission builder and we contacted Hughes performance with all my specs. Settled on a 2200-2500 stall converter. Should be nice and snappy but still a good street car. fingers crossed.