Originally Posted by Berserker

One possibility that hasn't yet been mentioned is whether the cam/crankshaft timing is correct. In the official shop manual, you not only have to align the timing marks, but also count the number of pins on the timing chain between the timing marks. If this hasn't been done, there is the possibility that all the damaged parts are a result of valve/piston contact. You might very well also have broken valve springs, bent valves, maybe even damaged pistons too.
The lifters in the photo are unbelieveably damaged; the camshaft they came in contact with is all FU'ed as well, without even having to look at it. I suggest: check your valve springs, valves, pistons, lifter bores for damage, if lifter bores are burred/scored they have to be honed out (oversize lifters are available), replace any damaged parts, get a new, stock camshaft and lifters, new timing chain and sprockets, prime the lifters before installation, install the camshaft-making sure of proper alignment with the crankshaft, smear generous amounts of assembly lube on the BOTTOM of the lifters and on the cam lobes PRIOR to installation. Remove the spark plugs and HAND rotate the engine, checking for any feeling of mechanical resistance (you shouldn't feel any), then button it up, replace the spark plugs, and it should run fine.