I would assume it means a "short block" engine, as opposed to a "long block" engine used with manual transmissions.
Yes, Brakes can be used in Auto transmission car when the Engine is off.
That would be a 4L60E transmission.
You should be able to. I have a 96 engine and auto tranny in a 91 model lsi hardtop. Everything works great.
The 4L80E transmission
That would be the 4L60E transmission.
An auto transmission provides controlled power to the auto. Basically is adapts the output of the engine to the drive wheels. There are often multiple gear ratios as speed varies.
If you mean automatic transmission, engine oil will ruin the the seals and friction material. Do not drive, change the fluid immediately.
It definitely is a possible cause of it jerking, if it's not an engine mount, service the transmission
Auto Transmission Fluid
Auto? dipstick at rear of engine
4.3L Engine w/Auto Transmission: 13.0 quarts / 12.0 liters 4.8L Engine w/Auto Transmission: 13.4 quarts / 12.7 liters 5.3L Engine w/Auto Transmission: 13.4 quarts / 12.7 liters 6.0L Engine w/Auto Transmission: 14.8 quarts / 14.0 liters As a side note, there are other various combinations for manual transmission, optional air conditioning, or optional engine oil cooler. The capacities provided are a good starting point if your vehicle has these other options. Also, these are dry capacities. A simple drain and refill will not require as much coolant.
A Gm 700R