TDI into an 80

Have got an 80 inch which has a series 2a box and 2 1/4 petrol which has given up the ghost.

Will a tdi fit and still allow me to retain the lights in the grill. If not, what diesel could I fit.

Then, with the extra power, what brakes will do the job?

My guess would be that a TDI would be too heavy, especially if you have narrow front springs. Also we have a S3 with a 300tdi and full intercooler set-up and it regularly eats the 2wd gearbox and does halfshafts and diffs if given the beans.
A decent 80 should be given the respect it deserves now. Find a decent 2 litre or if you have a to a good 2 1/4 (I quite like these in a 52/52 80).
If you want to do diesel us a perkins prima out of a Montego diesel. Not too heavy and quite an easy conversion. Try Steve Parker for the kit.
Brakes:
Use any LWB Series brakes, drums, cylinders and back plates etc. If you have the original 80 master cylinder you will need to change to Series 2 with an adaptor available from Radford brothers. Best drums for the front are LWB station wagon which are wider than anything else and stop like it has discs. If you want a servo use a remote one plumbed in somewhere neat.
Disc conversions are expensive and a waste of time; an 80 is only small and light.

Put a 2.0 petrol in! or any series 4cylinder lump! Cutting a series 1 80" about is not right!