GM Break off bolts, what & why?

[Samckitt]

I fond these on ebay the other day, check auction # 260227546825.

Obviously they are some kind of bolt that the head twists off once torque is reached. I assume they are for some type of racing that the motors have to be the same setup, like IROC was. How would you get them out once you need to tear it apart? And why are they so expensive? Auction now is at $305 for just a few bolts?

Text from the auction:
Set of break off bolts set to the proper torque, same as 602 604 motors. Email me with any questions and good luck bidding!!!!!!!!!!!!! Auction is for exactly what is pictured, there is no inscription(GM) on them but most rules do not require the logo on them especially when they are rusted and you can see them anyway. Shipping will be a flat fee of 15.00 in the cont. U.S.

Pic:
https://static1.pt-content.com/images/pt/2008/04/b1e0_1JPG-1.jpg

[HILROD]

I wonder if those are for "sealed" motors. You'd be able to mess around inside and seal them up again.

[JWilson]

Crate late models on dirt. 602 and 604 engine part numbers. The crate engine classes level the playing field so that driver/chassis setup makes the difference. Cheater bolts to disguise un-sealing a sealed engine un-levels the playing field for those who don't like level playing fields.

[tumper93]

Gm used them on steering column mounted ignition switches on geo's also. They worked really good. To remove just hit with a chisle counter clockwise and they could be simply unscrewed, if one wouldn't come out you could grind a slot in the top and use a screw driver. This has been my experience with them anyways, never on a motor!!

[Samckitt]

That is why so expensive then. So you can cheat & not look like it. Hmm...

[scubasteve]

we use a type of bolt where i work (Boeing) they are used on close tolerance hole +/- 00.02 and on sealed parts, and they are a paint in the butt to get out!!