I am working on a 454 mark 4 engine. It was recently rebuilt stock and I wanted to change intakes,cam etc. I noticed that the timing chain has about 3/4" of flex in it. This seems way too much. Not knowing much more about this engine, I assume it was line bored? How do I remedy this? I know they make an offset but how do I determine this if a new stock chain fits the same?

Sounds like a LOT to me!

You don't. You infer it from the chain (a NEW one, not a used one with ????? miles). You know that the cam journals didn't move so that only leaves one thing that could have.... the mains.

Is this engine out of the car? If so, I'd be going inside that sucker just to be safe!

Change the chain. You already have everything apart. It is cheap insurance. Don't use the cheap factory style chains. Get a Cloyes. They do not stretch. I pulled the Cloyes out of my 406 after 11,000 miles and it was as tight as the day I put it in.

I replaced the chain today with a cloyes and it fits well. The old one will not fold up upon itself. It binds at each link and therefore introduced the play. The question being, how did it get like this?

<font face="Arial,Verdana" size="2">Originally posted by mdd71:
I replaced the chain today with a cloyes and it fits well. The old one will not fold up upon itself. It binds at each link and therefore introduced the play. The question being, how did it get like this?</font>

Inferior design, shoddy machining, made in China parts. That's how.

It was actually made in England,just as bad as China in this case.