Chevrolet Repair: 77 chevrolet 305 no start, chevrolet 305, compression test

Question
Hi Van I have recently replaced the 305 engine in my 1980 chev 1/2 ton, with a 305 from a 1977, I had no problems with the changeover.  The engine was running great for 2 weeks, then one day seemed to have no power so I left it alone overnight, tried it this morning and the carburetor is spitting gas out like a shower and the engine is spitting and trying to fire but will not run, please help me, I am new to older engines and was told the chev 305's had cam problems, I believe it may be timing what should I do next.  Thank you

Answer
Hi Joey,
A 77...doesn't that one not only have a carburetor, but POINTS also??
Don't jump on that cam just yet. A compression test can tell that later if needed.
But adjustment of the points, for not only gap, but dwell also, is necessary.
I am very thankful for electronic ignition, and fuel injection, cause there were always points that needed adjusting, and replacing.

So if it has points, that is where I would start.

Write me back, and let me know if that doesn't help.

I assume that spitting of the gas is up out of the carb??

There is always the possibility of sticking intake valve, timing chain problem, etc, but do the ignition first.
Generally a worn lobe on a cam won't hold a valve open, but rather keep it closed.

Make sure the fuel pump is supplying enough fuel to the carb also, and if flooding seems to be the problem, a saturated, heavy float could be the problem.

Van