mwg88
hey guys.. need some advice if anyone is able to help?
i have a 76 mk2 1600 auto and have been having some issues with losing power / bogging down under load.
if I'm driving up an incline / hill or getting onto the highway / need power to overtake on the highway, the engine
power just decreases, and regardless of accelerator position it just loses power and speed, eventually will cough
and
splutter, seemingly a few minutes later the issue is gone and i have power again.....

 
That sounds fuel related. The carby starves of fuel under load to the point where it finally coughs & splutters, as you say, then a few minutes later, of little or no load I'm guessing, the carby bowl has had time to fill back up and away you go.
 
If you have a fuel filter installed, and you should, then I'd start with replacing it with a new one. If you can, get one which allows you to see the level of fuel in it, then if it still coughs & splutters when under load, turn off the motor immediately and check the level in the fuel filter. If it's low or empty, then fuel supply will be your problem and you may need to look at the pump, as well as check that the pick-up in the tank is not blocked.
 
My 2¢ worth.

Have you replaced the condenser?
I had a similar issue years ago & that's what it turned out to be.
 

Distributor Base Plate.  These wear, and flex under load, very common problem with the Autolite and Lucas dizzys on the kent motors.  Hunt around for a Bosch.  I had exactly your problem years ago and thats what it was

i had a similar issue on a stock 1600.    there is a gauze filter in the stock carby that got blocked up a bit. enough to restrict fuel flow into the bowl.   once i cleaned that out it worked fine

i just removed it and cleaned all the junk off with throttle body cleaner.  i thought about removing it all together but the fact is it still blocked up even with a filter.