can anyone help

i am interested in buying a gti i have seen for sale it is a 83y reg 1.6 is this right i did not think u could get one of these

Check the chassis number, its probably a 1982 (C year identifier on the chassis number) that's been built a couple of months before it was registered, then sold in the next 'year' gaining a Y reg.

or they have replaced the original 1.6 with a 1.8.

check the original log book, or online search on the RAC website should tell you.