No start after timing chain replacement

It was not running before this job. When I pulled the valve cover off I discovered the chain guide on driver's side was broken. From what I have read this is common on these older trucks. I did notice that the cam and crank spocked did not look like they were exactly in the 12 o'clock position. Both had their keys at the top but I remember them looking like they were just to the left of 12 o'clock. Maybe more like 11:55. Close but not 12 o'clock. I'm thinking as much as I hate it I'm going to have to pull it all apart again. The cam sprocket that came with my kit from NAPA didn't have holes in it to wedge something through it which made torquing to specs a complete guessing game. It is impossible to hold the cam still and apply enough force to be sure. While I did this I had an assistant monitor the crank to be sure that as I torqued the cam bolt the chain didn't move on the crank. Since I'm going to have to do another tear down I'll purchase another cam sprocket with the holes drilled in it.
Also, it isn't easy getting that oil pump back in without slighlty bumping the shaft which turns the distributor. I know it would take quite a blow to move the crank. However, I'm wondering if while reinstalling the oil pump I could be allowing the shaft to turn slightly causing me to be off by say one tooth on the gear which drives the disributor?
Anyone have any links to pics showing what the distributor drive gear should look like once the oil pump has been installed with engine's #1 cylinder at TDC?

I appreciate all the feedback so far. I've been out of town and then sick but this afternoon I decided to take another crack at this truck. Following Zanegray's advice as well as what many others have posted in the past I thought it must be the oil pump/dizzy that is creating my headache. I put the engine at TDC #1 cylinder by removing spark plug and rotating engine until I could feel pressure and then located timing marks on pully. Removed the dizzy and oil pump. Practiced reinstalling the pump a few times before adding oil and tightening. Afterwards, I looked through the dizzy hole on the timing cover and it looked like I've managed to position the shaft so that it is at the 11 and 5 o'clock position as described by everyone. Upon starting the engine it again ran for a few seconds (maybe 8-10) before shutting off. It will not start afterwards. I wondering if this truck has a shut off switch so that if there is low oil pressure it will not allow the engine to run? If so do I need to reset something?
I hate to go this route but it looks like I'm going to have to take it all apart again. I'm not happy about it but I'm also not one to just give up. Maybe, I missed a tooth or something when installing. It's amazing that you can be so sure about everything but when the problems show up you start to second guess yourself. Another question, what would happen if it where somehow installed on the exhaust stroke? My assumption is that it would run extremely rough if at all.
Again, I find your tips to be vdery helpful and appreciate any help you may offer. This will probably take me some time to complete due to a busy schedule but I will let everyone know the outcome/progress.

Too late as I have already pulled everything apart again. After removing the valve cover and finding TDC I noticed that the camshaft's key is not quite at the 12 o'clock position. Very close but not exactly. A little past the position. The crank's key is dead on the 12 o'clock spot but if the cam's key is at 12 even the crank is a few marks off on the pulley. In other words, with cam at 12 o'clock the crank looks to be about 15 degrees advance if that makes sense. So I am thinking that it must have been reassmbled incorrectly. Do you think it would hurt anything if once I remove the chain I bump the cam gently so that it is at a true 12 o'clock position before a assemble everything?
I feel like I am overanalyzing this but when it comes to timing it has to be right or as I am finding it will not run.
I am now looking for a new cam sprocket and would even consider using the old one. I know this is not adviseable but I cannot believe all the aftermarket camsprockets that do not have the holes drilled in them. The one with my kit is useless for anyone without access to air tools in my opinion. It is even difficult to get back off because of no way to hold the cam still while removing.