Breathless old girl?

Proud owner of a 300tdi (95MY) Disco 1 since May this year.

Vehicle has done 165,000 miles. Recently had a new timing belt and head gasket (proper job).

She seems to perform reasonably well and returns around 30mpg average but I have noticed of late that she is quite 'breathless' at anything over 3000rpm. She struggles a bit on long motorway climbs and when towing.

Am I expecting too much or does anyone have any suggestions (sensible please )

Check for air leaks and turbo hoses, fuel pump not right, blocked injectors

Does it rev to the limit in neutral or is it just under load it struggles

yer skip the simple things, dive in and rip the injectors out

Never tried revving mine past 3000

air filter,fuel filter, sedimenter. when were these last changed ?

how about checking that small dia black pipe that goes to the vacuum actuator on the turbo?
after your airfilter,hoses ect.