273 Engine will not start - Ideas?

EDIT LOL You and I were typing at same time

Get down to the basics, compression, fuel, spark. Maybe the cylinders are fuel washed. Maybe run a compression check on 2 or 3 easy to get to. Certainly throw a little fuel down the carb, and fuel been sitting may be a problem, make sure you use fresh fuel. If you have ethanol free fuel in your area, not bad to buy some of that, especially for lawn mowers and priming.

If you have a timing light, and have not played with timing, you can check the timing on the starter. This will tell you that the dist is working and timed as well as that the timing chain is in time.

Yet another thing, if wiring is a ?, is to simply jumper a lead from the battery to the coil +. Do not leave that there any longer than necessary for testing, and do not leave it connected while fiddling around getting ready. Prime the carb, connect your jumper, and crank it.