valve spring lift..

up to .500 lift is safe on stock springs.

here is the short belt diagram

Slow down there -- this statement "so i have been looking at b cams so i can get pretty steady increase across the band." isn't true. You're gonna notice a HUGE drop off of bottom end with that cam and the stock heads, and very little gain on the top end. And tired stock springs are known to float with the stock cam -- they'll be more prone to do so with the B. It's entirlely possible you'll get into valve float before you can access what little bit of top end gain you might get with the cam. Just because the stock springs are capable of more peak lift without reaching bind doesn't mean they won't float, or that it's a good idea to take them that far. You'd be MUCH better off saving your cam swap for when you do the heads and intake. I suspect you'll be very unhappy with the results of a basically stock engine and a B cam. One of my favorite quotes came from a fellow that frequented the sites for a while "Best performance mod - taking the B cam out of my stock engine and putting the stock HO cam back in."

Unless you're having some specific symptom - no reason to replace the timing chain as a 'precaution'. If the pump needs replacing - it's easy to do on a stand-alone basis. Save up for your heads -- and then do heads/cam at the same time. You'll much better off.

Don't forget the intake - it's the most restrictive stock piece on the intake side of things. If you want to do something that will add power/torque right now, get an intake on that thing, or have tmoss port your stock lower. For about the same price as a used B cam, you can have tmoss port your lower, and get MUCH more bang for the buck -- and the install is MUCH easier than a cam swap. And with intake/heads/cam/exhaust - you can start to look at maf and throttle body.

And yes - at 120K the stock valve springs are in no mood to handle the B cam.

Here's the best reference I know of to learn about cams. Open every tab and read up....

http://www.wighat.com/fcr3/