D2 Front Idler Question

I have a D25U with a 2A blade. The cat started out as a ag cat so it has the small idlers.
I do have another 5U that had a dozer on it and it has the large ldlers.
I know i will have to breakdown the track on both machines in order to change the idlers.This proceedure about the tracks can't be fun,but if it will help me just alittle,i guess it would be worth it.
I realize a d2 is in no way meant to be an effective way to handle large dozing jobs.A d6/d7 would surely be more adaquate.

Anyway,my question is.Is there anyone that has switched from the small to the large idlers on there d2 was there a big difference,or is it still impossible to grade with one.
OH YEA,there is just one more thing .Is it possible to remove a track pin to add or subtract a link if you make one of those little holder things that you bolt on the pad,and use the biggest/baddest hammer you can afford ?
THANKS AGAIN IN ADVANCE COMPRESSOR

I've seen a few critters that have had the tracks shortened 'cuz they were worn out and no more adjustment possible by doing just that. .taking a link out. Replacing a small idler with a larger one is gonna tighten the track up by itself.

As far as fine grading with a D2. .it might be possible but I can't do it without backdragging between every other pass.