I took my truck out for the first time this year.It stalled a couple of times till it had some heat.then it ran fine.After some errands I went to start it.This is when it gets weird.It cranked fine but didn't fire,when I let go of the key,it fired up.I shut off and tried again.Same thing.Drove home,shut off and tried again.Same thing.I have never come across this before.I put the batery charger on it the last 2 hrs,still no change.
It's a Chev 350 with GM HEI ,2yr old battery,Any idea's

1952 Chevy 1/2-Ton