With only engine oil on the "face" of the lifter, you can try it and see if it works. I would recommend engine assembly lube specifically for camshaft lobes and lifter faces, or use a good moly grease that most auto parts stores sell. Rub the moly grease onto the cam lobes, all the way around each lobe, and rub the moly grease onto the face of the new lifter where the lifter is going to contact the camshaft lobes. Use engine oil on the sides of the lifter that rub in the lifter bores in the engine block.
When you start the engine for the first time, make sure as soon as it starts to get the engine rpm up to about 2000-2500 rpm and hold it there for at least 20 minutes, then you can slow it down to idle, not sooner. This helps throw enough oil onto the camshaft to lubricate it enough for initial break in of the cam lobes and lifter faces.
Why are you changing lifters and not camshaft too? If the cam is worn or has a bad lobe it will ruin your new lifters.
If your going to go ahead and run it the way you have assembled it, or even after using the moly grease, a good way to verify that the lifters and cam seated in correctly is to run the engine for maybe 50 or 100 KM and then take the top of the engine back apart, and pull the lifters out one at a time, and verify that the face of the lifter has a completely round contact wear pattern which means the lifter is rotating correctly. A bad contact pattern can look like a straight wiping across the lifter face, or a partial rotation of the lifter which will look like when you lay on your back in the snow and move arms and legs to make a snow angel.
IF a lifter does not have the correct circular pattern, and the lifter still has a crown the lifter face, you can restore the face of the lifter by rubbing the lifter face in a figure "8" pattern against a sheet of 600 grit sand paper. Count the number of figure 8's you do. When you get to 10, then rotate the lifter in you hand and do 10 more figure 8's. Do this several times until the lifter face is evenly sanded. The figure 8 pattern is so you keep the crown in the lifter face. Then coat the lifter face and cam lobe with moly lube, reassemble and run it 20 minutes again to break it in, then take it apart again after another 100 KM and recheck. I did not make this up. David Vizard describes this procedure in one of his books. Hope this helps.
