I'm having my 350 that died rebuilt again and the machine shop said the cam was salvageable, but the lifters were not. I thought you weren't supposed to use an old cam and new lifters, or is it the other way around?

 

well you can use a new cam with new flat tappet lifters or a old cam with new flat tappet lifters or a old cam with a matched set of old lifters

 

cool, i thought that was the case. thanks

 

If the lifters are shot, the cam is too.

 

What if you just have few that are not pumping up the way they should? That's what I have going on with my truck. I don't think the cam is bad it's just did this after it sit for awhile apart. One or two lifters refuse to pump up.

 

If the lifter foot is visibly cupped, the cam is also finished.
Lifter are not flat, they are slightly convex. put two together, foot to foot. if they will not rock slightly, one or both are shot.
Usually the cam is shot too. Flat tappet hyd cams are cheap. Its not worth trying to save the cam unless it is a expensive custom grind and looks and measures pristene. A new $69 Summit generic cam and lifter set is hard to beat. Your hyd lifters are either infected with dirt/metal fileings (could be a warning of internal engine wear) or cheap offshore junk.
When I tear a motor down I'll only save the cam if all the lifters are good. If any are cuped or flat, I toss the cam.

 

Your having a engine rebuilt and your trying to save 100.00 by using old cam? When the motors back together, you will be kicking yourself everyday.

 

well, it was a "new" crane 2050, and the engine died with only like 1500 miles on it. I guess it does make sense to just by a new cam and lifter set, think it's only like $150