I just had a kid stop by the shop who's got '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" 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?

 

Mine's been working fine for 5 years, turning an 0.590/0.590 lift solid roller cam with healthy spring pressures. A friend used the ED set on a blown 383 making 1,125HP with a big solid roller cam, and never had a problem with the ED set, even though he was turning close to 8,000rpm.

 

I ran one in a 350 i put together. Came back apart a few thousand miles later due to bearing failure and it was pretty loose. I didnt run the oversize gear though.

Is the crank gear and cam gear aligned correctly?

 

Wow, guy here in town had the same problem not too long back. 383 built by a local speed shop and it snapped the ED chain in the first 1000 miles or so. They took it back fixed everything and put a STOCK timing chain back in and it munched that one in pretty short order.
I felt it was the machine work but they said it was the water pump locking up...... I am in no way convinced that the splined shaft on the water pump is stronger than a timing chain but who knows.
He sold it cause they could not figure out what was wrong for sure and he didn,t want to keep putting money in it.