My engine cranks over but not run can you help?

I have the truck listed above xl model. I recently bought from some kid that lived on a farm who stated that he worked part time at the race track. When I bought it he had replaced a bunch of stuff and it started up but needed the clutch bleed. So I took it and bleed the clutch and started it up and it ran good. I drove about a mile and a half and it was apparent that it was massively overheated. I couldn't tell because this old truck doesn't have a working temperature gauge. So I got it home opened the hood and noticed that the what looked like a radiator was in fact an A/C condenser. The kid had hooked the A/C condenser up to the main in and out ports for the water in the engine. Once the hoses where hooked up there was no way to add water and that's why it overheated. So I went and bought a radiator put it in and drove the same distance and back and same thing so at that point I realized the. Water wasn't flowing ei the water pump was bad. So replaced that. After replacing the water pump I tried to start it and it didn't stay running and so on and so on I figured out I had blown the head gasket. So I just now finished replacing the head gasket. And it wont start I hooked everything up but nothing it cranks I checked the starter it's working and I checked the gas I can see it squirting into the carburetor. So I got gas and I checked I am getting good compression. I am not sure how to check for spark but I believe that is my problem. How would I go about diagnosing a no spark problem? Also I am not sure if I have the distributor turned to the right the degree.

Okay so I figured out that I was in fact not getting spark do to the previous owner. He had cut a bunch of wires one being the power wire to the coil pack. I spliced it together and turned the over it almost started. I am just getting a lot of backfiring and it wont start still. But it is getting gas and spark.

Ok I have a 1986 Ford Ranger 5 Speed 4x4 I was driving home one day and was backing into my driveway and I killed it, but then it wouldn't fire it would crank for ever but would not fire we think it was something electrical cause it happened all of a sudden like a relay went out or something. I'm not sure what it would be or where to start any help will do.

Hey I did like you said and There was no blue spark whats the best place to start?