There seems to be a bit of confusion and myth, so I think it's time to clear the air a bit.
Head gaskets require flat surfaces on both the block and the head to seal properly, the block is heavy enough that it usually won't warp, heads on the other hand will and do warp very easily. The factory allowable tollarance for warp is 0.003 in. (not very much), any thing more than this will require that the head be surfaced to make it flat again. This is no big deal to have done, just a little work to remove the manifolds so it can be done.
When reassembleing it is necessary to torque the head bolts in the proper sequence. This needs to start at the center of the head and work evenly towards the ends. also it needs to be done in steps, as in step 1 torque all 10 bolts in sequence to 25 ft. lbs., step 2 torque all 10 bolts in sequence to 40 ft. lbs., step 3 torque all 10 bolts in sequence to 55 ft. lbs. There are reasons why it needs to be done this way, if one torques the center bolts to full torque and the end bolts are loose, it will warp the head, and by torquing in steps it will allow the gasget to seat/seal better and help to prevent blown gaskets in the future.
You may have noticed that I put the final toruqe figuere at 55 ft. lbs. instead of 49 ft. lbs. like most manuals show, this is because at 55 ft lbs. the seal is better and gaskets won't loose seal unless the engine is sevierly overheated.
As for head bolts, the A series engine uses 2 different ones, the one that goes in the center right (distributor side) is different from the other 9. the oiling system for the valve train (rockerarms) feeds oil through this hole, putting the wrong bolt in that hole will restrict oil flow to the rockerarms and valves. Under high rpm conditions if the oil is restricted to the valve train it will cause excessive wear and possably nonrepairable damage. I have seen some so bad that the rockerarm shaft had grooves worn into it deep enough that the valves couldn't be adjusted.
hope that this helps and good luck.

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You're right, if it's within the factory specs it doesn't need to be surfaced (milled). Problem is, every shop I've ever talked to says "oh that's not right, you gotta mill 'em every time or you'll warp the gasket ... and it's only $ to do it - it's cheap insurance". What a bunch of baloney -- as if the factory doesn't know anything. For or a stock or mild engine, it is more important to get the block and head scraped clean (no old-gasket residue) and get the oil off the surface before putting the new gasket on. I use a little starting fluid (ether) to get the oil off. As rgrinder explains, torque the bolts in pattern to the correct torque steps (use a torque wrench) and it'll be just fine.

If your engine did blow the head gasket, use a quality straight edge and a feeler gauge to measure head warp (if any). A good straight edge is a precision device, so you might have to round up an old mechanic friend or have a shop check it. It usually doesn't warp 3/1000 of an inch even after blowing a gasket. But it can, so it is important to check.

Another thing to check when reassembling an A series is that the bolts holding the head down are lightly oiled. Also clean out the bolt holes as they easily fill up with crap and the bolt bottoms out. Also this can be a problem if the head has been machined alot. I lost a brand new CA race motor that lifted at 9000rpm and let water into the cylinders, it hydrauliced and blew the head into 4 pieces !!!

You are right on this, and I should have included it in my original post.
everything must be absoulutly clean, if there is any of the old gasket left on any surface, or if you use any kind of sealer on the head gasket, this will cause the gasket to fail again.
cleaning and lightly oiling the threads will allow the bolts to torque to spec.instead of binding up and giving a false torque reading.
may be when our webmasters return from thier vacation, we can convince them to set up a tech or help page to help those who don't have the experiance some of us do.