If this is a used cam, have a machinist look it over and if he approves it, use new lifters, never trust that someone kept the old lifters in order, beside the fact that being in a different block can also be an issue to a lifter that is broken in to a specific lobe at a specific angle.
If you have to pay anything for a used cam... don't. If for any reason you have a lobe go bad, it will run filings throughout your engine, and you could damage a lifter bore getting the damaged lifter out.
To identify your cam you can take a dial caliper and measure the difference between the baseline and the overall lobe lift, then multiply this by 1.5 and you should get your advertized valve lift. Then you can compare your findings to Comp's specs.
The first 2 lobes next to the distributor gear should be exhaust and the next 2 intake on a big block Chrysler.
Remember to run a zinc additive in your oil for a flat tappet engine, or in an engine with mild valve springs, an oil that still retains higher levels of zinc, like Rotella, and maybe someone else here knows of other oils that will work.
