What trans is in a stock 1984w150 Dodge Truck with a 318?

[Bad B-rad]

I just bought a 1984 w150 stepside, 4X4 with what I was told is a rebuild 727.
I thought 727's were used on big blocks, and 340's, and small blocks had the 904(except 340)
Is the stock 1984 truck 4X4 trans a 727?
and if so, is it as strong as the muscle car era 727's?
I was toying with the idea of putting a 5.7 Hemi motor in place of the 318, but figured it would just roast the trans.(318 at like 150HP vs the Hemi's 370hp)
Thanks for help.

[John_Kunkel]

Your truck has a 727 and the only difference between the BB 727 and the SB 727 is the case. The SB 727 can be built to be as strong or stronger than the muscle car era transmissions...plenty strong enough for a 5.7 Hemi.

[Bad B-rad]

Sweet, I thought they were 904's.
Thanks