Having recently changed the SU pump on my TF1500, (the previous owner had asked a garage to fit a new pump and a late MGB pump had been fitted, which was not to my liking) I did some research on the Internet and found the following:
L (low pressure pumps) – These are found on the T-Series (TA, TB, TC, TD and early TF) and earlier MGs.
They develop up to 1.5 psi and have a flow rate of 1.3 pints per minute (9.6 gallons per hour).
HP (high pressure pumps) – These are found on late TF, MGA, Z Magnette and early MGBs.
They are the same outline and size as the low pressure pumps or sometimes come with a longer coil housing (referred to as a High Pressure/Long Body pump).
They develop up to 2.7 psi and have a flow rate of 1.1 pints per minute (8.4 gallons per hour).
LCS pumps – These were used on the MGA Twin Cam and on the Austin Healey.
They use the long coil body of the High Pressure/Long Body pump and have a large, rectangular pump body on them.
They develop up to 3.8psi and have a flow rate of 2 pints per minute (15 gallons per hour).
AUF 300 series pumps – (now AZX 1300 series) – These are found on all of the later MGBs plus many British cars of the 1960s and later.
They have what is called a “plain air bottle” on the inlet side and a flow-smoothing device on the delivery side.
They develop up to 2.7psi (AZX 1307) or 3.8 psi (AZX 1308) and a flow rate of 2.4 pints per minute (18 gallons per hour) for both types.
My car was fitted with an AZX 1307.