Ok there were four different models and two different bodyshells
The MGA 1500, 1600, 1600MKII and Twin Cam
Which were all available as a roadster or a FHC
They were made from Mid 1955 when they replaced the MGTF till mid 1962 when they were replaced by the MGB
They all used the BMC B-Series
1500: 1489cc 68bhp@5500rpm
1600: 1588cc 80bhp@5600rpm
MkII: 1622cc 93bhp@5500rpm
Twin Cam : 1588cc 108bhp@6700rpm
Production
1500: 58,750
1600: 31,501
MKII: 8,719
Twin Cam: 2,111
The 1500 had 4 wheel drums, the 1600 and MKII had front discs and the Twin Cam had 4 wheel discs. There was also a model called the De-Luxe that used up the Twin Cam chassis parts after the Twin Cam was discontinued including the 4 wheel discs but with a 1600 Motor.
All the OHV valve models had standard Bolt on disc wheels with option centre lock wire wheels. The Twin Cam had standard Centre Lock perforated disc wheels
Once again its me to the rescue with MG information