Has anybody dropped an LS motor into a stock framed S10 and installed full length headers? My nephew is having hard time finding some that fit.

There are a number of publications (JTR/Mike Knell)that address s-10 swaps. Transdapt/Hedman Headers manufacture swap kits with long tube headers. Hooker Headers manufactures long tube headers. There are also a number of blogs that address the S-10 swap. I think Sanderson Headers also address' this swap also. Hope some of this helps and good luck.