I have a set of hgt grooved-ventilated disk brake and wanted to fit them on my 1.4 SX , but they don't match.
Could you give me the specs of the disc brakes on the 1.4 and for HGT ?
Cheers.

I have a set of front calipers for a 20v for sale matey

You can't use HGT disks on a 1.4, Completely different size wise, you can however use 1.8 calipers, which are worth the upgrade imo. (had to use them a couple of weeks back and oh my god they worked!)

Your calipers will take a 257mm disc, HGT's are 284mm so you'll need some caliper mods to get them to fit.