cross over-thermostat housing

[west tex man]

Have an old 83 Chev 6.2. Had a dead miss in it so planned to pull the head on it. Pulled the coolant cross over-thermostat housing in anticiption of pulling the head. Found out I didn't need to pullthe head so proceeded to reinstall the cross over. I cracked one of the flanges while tightening it down. Obtained several more cross overs with the same result. As bad as I hate to admit it, can't figure out what is going on. Am wondering if these cross overs become brittle after many years of use. Was wondering if any members out there have run into anything similar to this. Would appreciate some advice you could give me.
West Tex Man

[6.5TDTahoe]

If you didn't have a click type properly set torque wrench you probably just over tightened the bolt. IIRC the gasket has a lot of crush at the outer end. Jim the web site owner reported this happened to him installing a crossover.Be glad it isn't a dual thermastat 6.5!Use small stainless washers for spreading the torque load.

[john8662]

Another thing to always remember. Use the gaskets, do not use just RTV on the crossover, you will crack it.

Get the appropriate water crossover gaskets from the auto parts store, I prefer to coat these gaskets with the grey waterpump sealant in small tube.

J

[west tex man]

Appreciate the advice and information, men. I had wondered about over torquing, about the gaskets(was making my own out of one thirty-second gasket material), and was going to use flat washers under the studs on the last one I tried but didn't. I'm a little slow. How do you ID a red 6.2 block. I've heard of them but that's all I know about them. My engine is a Mr. Goodwrench motor with about 350000 miles on it or more.
Thanks again. I'm located in Kermit, Texas.

[jogl]

I cracked mine too. Creative use of RTV in and around the crack is holding so far.

Almost made me swear when I saw coolant running down the V of a fresh rebuilt engine.

JP.