The engine in my 69 has about a billion miles on it,I put it in the car in 1978.It's a very mild 350 with older fuelie heads,350HP Hyd.cam and factory alum. intake/Holley 600. it has run fine for all these years but last fall,after a long hiatus when it was only started occasionally,it has become very hard to start.It spins like mad,no battery/starter issues but just won't fire.It sounds like there are no pistons in the motor.
It's getting fuel,I can work the throttle and see the accel.pump shoot fuel.When it finally does start,it runs real rough like it's only on a few cylinders and gradually picks up until it's OK.
I've tried another coil and replaced points/condenser-no change.
Any help would be greatly apreciated.

Have you checked compression?
Sounds like it's low until the engine warms up.
Once it starts does it pop through the carb? If so most likely the valves are sticking in the guides.
Dale

i was thinkin hung up rings equaling low compression...also, the valves could be hanging open in the guides, due to build-up on the stems...had that happen on a 65 tempest with 215...i ran fuel injector cleaner thru it, that cleaned the stems off, and it ran great after...i ran the cleaner thru the brake booster vac line, by the way...i have 1 of those bottle hangers for that...works ausumn even on the old stuff...

I finally figured this out-The car was running worse every time I did manage to get it started-super rich,washing out the plugs and making my eyes water! I ran compression-it's not great,I didn't expect it to be with the age of the motor,but it's consistant and passable. I borrowed my son's carb and the car runs great with it-starts right up,goes down the road effortlessly,just like I remember.I bought a rebuild kit for it today and will get it squared away soon.Thanks for the replies and the help,guys!

Good News! As an afterthought, you might want to check the oil andor change it. I had an old Holley 750. Rebuilt it, but might have picked up contamination from the body fuel line and wasn't controlling the gas flow at the seat. We pulled the dipstick and smelled excess gas in the oil. Just a thought to lessen chances of further insult to injury. Happy Motoring!

Carb rebuild...mybe check worn bushings in the Dizzy, new condesor, pionts and timing check.

The old holley got a lot of play on the butterfly bushes?...if so its a waste of time rekitting without doing these.