[DK914]

The exhaust studs are pulling out of the heads on my '74 2.0, not an uncommon problem, I'm told, for 914s and early Vanagons. (Terrible feeling when you're torquing 'em down and the ratchet suddenly goes limp in your hand.) They've been repaired before, some with helicoils and others with "Timesert" threaded inserts. So basically it's a mess.
The heads are coming off soon. My question is, can the damaged holes for the studs be welded up (after the damaged inserts are removed) and re-tapped with reasonably long-lasting results? Does anybody have experience with this? And why did VW/Porsche come up with such a cheesy exhaust arrangement in the first place?!!!!
TIA for any help you guys can provide. I feel better already after venting.