Re-torque - Is it necessary?

[dom14]

I would always recommend re-torquing the head bolts

you DID use new bolts didnt you....
you DID NOT use the old head bolts.........

I am planning to do the bottom end of the same engine in few months time, which includes decking the block surface, honing the cylinders, new ring set and perhaps new big end/small end bearings as well, and even perhaps rebore if necessary.
For that reason, the new set of head bolts I bought for it is still in the drawers.
However, the guy who sold(rather gave away) the good cylinder head to me assured the head bolts were 'brand new'.
What he meant was he bought them new and fitted and within a day or so, the bottom end(big ends) of the engine blew up.(R31 Skyline)
So, they were good quality head bolts(genuine) but used once.
In reality, they can be better than the possibly aftermarket set of head bolts that I bought from ebay.

I also used anti seize(fine graphite powder) lightly smeared on the threads of the head bolts, just to make sure
the 'cringing' of the head bolts as they are torqued due to excessive friction inside the threaded holes on the engine block won't give
me any incorrect readings on the torque wrench. I also spent an unusual extra time by adding extra steps to torquing steps.
I'm hoping all that extra care will yield some favourable results for me.

Thanx for the tip about retorquing @Bigcol

What is your opinion on my second question(whether I need to re-adjust the timing belt after re-torquing the head bolts)?

Thanx
Cheers