4sp or 3sp: Stupid Question

[DirtyLittleSecret]

Okay, I'll ask a stupid question...I thought I had a 4 sp in my wifes 78 K20, but my neighbor was adamant that its a 3sp.

Anyhow, the shifter shows L, 1, 2, 3, and R.  Did Chevrolet consider this a 4 sp or 3 sp?  I know that some manufacturers didnt consider L a "gear".  Im concerned whether I need to run 80W GL5 or ATF in the transmission.
Cheers!

Edit: Oops.  Just realized that we've got a drivetrain section.  If it needs to be moved please feel free to do so!

[Captkaos]

You have a SM465 if it has Low.  It is a Granny 4 speed as it has 4 forward gears.  It takes Gear oil not transmission fluid.

[DirtyLittleSecret]

Thanks Chris for getting me up and running & responding so quickly!  Good to know Im not loosing my mind.
It really is ridiculous how low L is, but I wont complain.

[Captkaos]

Yeah, it is really low.  I generally didn't use it during daily driving on my 81 K10.