Starter issues - Need some insight

[cbehymer]

I just put a new starter in my 68 GMC {305 V6).
When I hit the key it tries to engage the starter but it doesn't crank the engine over.

The truck sat for about a year and it was running fine before I parked it.
I can turn the engine over by hand with no problems.

I noticed that after trying to start it when I turn it over by hand I can hear the bendix releasing and clicking back into place.

I am open for any suggestions at this point.

Thanks in advance for your help.

Chris