Why am I seeing some who recommend not reusing the head bolts? I cleaned and checked every one and they look perfectly fine and identical to my old school bolts except for a smaller head. The ones under the valve cover area are plain steel but the short ones along the bottom edge are a silvery plating. They have 1/2" socket head but otherwise they are identical to early 70's. On disassembly the short ones had about 55 lbs torque and the longer ones had about 70 lbs.
Paul

The change in head style was to make sure that nobody confused them with regular older bolts because the new style bolts with the small head are torque to yeild bolts , they are ment to be a one time use bolt because they are as the name says stretched to their yeild point supposedly to get maximum clamping force out of the fastener .
Some people reuse them and some of them get away with it , I wouldn't because since you've torqued them to their limit once it's pretty hard to do it a second time with much success

Thanks for the input. I am getting conflicting advice on the bolts. Some say the smaller head is so you can get to them between the rockers, and some are saying that TTY bolts are on Fords and Chevy LS1's but not Vortecs. It would be nice if the bolts had some kind of head marking if it is non reuseable. Even the timing cover has wording cast into it telling you it is nonreuseable (although it really is).

Bump for 1 last question. I plan to use a set of old school head bolts so that issue is done, but what about the stock Vortec bottom end bolts? Are the main cap bolts std torque bolts and what about the PM rod bolts too? Thanks,
Paul

I dont think they are a tty bolt. Ive reused them with no problems.

google it , there are many opinions.