LT1/4 Extreme Duty timing chain breakage

[Notorious]

I just had a kid stop by my shop who's got a '93 383 LT1 that was built by some performance builder in the area. Twice within 3,000 miles he has broken GM extreme duty timing chains with the expected subsequent results. Anyone heard of or had any problems of this nature? He doesn't really know what all is in the "package" he bought except that cam lift is 510-540 and it has some sort of double valve spring. Unless he has way too much spring pressure for this sort of chain or a serious misalignment problem, I don't really know what would cause this, but I do intend to take a look at it for him. I'd like to think a performance shop would have checked piston to valve clearance but who knows. They fixed it for him the first time but this time it was near the end of the warranty period and he doesn't even want to take it back to them and I can't blame him. He currently has it torn down to the block. Any ideas on this, anyone?

[contraststriker]

if he has an electric water pump, swap in a double roller timing chain. Summit sells them for $42, and they're better than any GM LT4 blah blah blah kit. Beats me why people waste their money on crap like that.

[Notorious]

Originally Posted by contraststriker

if he has an electric water pump, swap in a double roller timing chain. Summit sells them for $42, and they're better than any GM LT4 blah blah blah kit. Beats me why people waste their money on crap like that.

He doesn't have the EWP but I don't think I'll have any trouble convincing him that's the way to go. Hell, the Cloyes True DR is only $75. That's what I use and the savings over the GM ED part basically paid for my Meziere HD pump. I put a DR in anything I tear down, even if it's just stock. Why not? Stock ones stretch in no time. By contrast, I used one Cloyes set in three oval track engines over a four season period and it never stretched to any significant degree.