Could my 340 block be filled?

Started up my car tonight and let it warm up to temp. Set the timing and let her run for a while. After shutting the car off for about 15 minutes and then turned the key and she started right up. Shut the car off again and let it sit a while and then turned the key and she started again. That has not happened in the year and a half that I've owned her. Didn't get a chance to go for a ride but I think finally she can be considered dependable. Hoping to not have to call AAA for a while. Will get a chance Sunday to take her out and give her the real test. Pretty excited
Well...Still have issues. After I had a friend come over and weld my Z Bar bracket to the frame I was able to take my car out for a longer cruise than usual. I went to get gas a few miles from my house and when I started her back up she turned for a little while before firing. Since the car was warm I thought it should've started quicker. No big deal....She started. I continued on my ride. Saw a nice 70 Dart Swinger and we both waved to each other. I got a bunch of thumbs ups from passers by in cars, trucks and even motorcycles. Made it home with no issues at all....Seemed to be running great and sounded just as good. Then I put the car back in the garage and parked her. About a 1/2 hour later I go down to turn the key to hear her fire up assuming my no spark issue is behind me and I can be confident when I cruise. No luck at all.....Right back where I started...No spark when warm after sitting. Went into the garage today after the car sat all night and she fired right up. Now what? I have replaced the entire distributor most recently thinking it was a pickup issue.