Push Rods, Reassembly
 

Well the guy that was suposed to rebuild my 454 started the job and left me high and try. When he took out the push rods and rocker arms they did not get marked for their location. Do I need to buy all new push rods and rocker arms now? I was told that if reusing them they need to go back in the the same way they came out, and I just 2 vavle covers full of parts.

If it is a flat tappet cam, the rockers should go back on the studs so they match up with the valves they have 'grooved' on to but if you inspect the rockers and smooth (gently with fine sand paper) the contact tips, there should be no reason why they won't still work fine. If it's a high lift cam, you may want new rockers. If the valves are new or have been re-done then you'll be fine, just inspect the rockers carefully. The Hyd lifters will take up the diff in heights and if it's solid, you'll take it up in lash.
As for the pushrods, they can just get cleaned and put in where they fit. If they're two different lengths, one's intake (short) and the other's exhaust (long), you'll know when you fit them. Replace any of them if they show signs of pitting, damage, bends or ware. Check each one's tips and the ball for ware too. If you find a set for cheap, replace the whole set.

Make sure to soak all the rods in Clean oil prior to install and use assembly lube on the pivot ball, the push-rod cup on the rocker and the valve stem prior to assembly.

Good Luck!