Board manager wont install esp8266 version 1.6.5

I cannot install esp8266 version 1.6.5-947-g39819f0 using the board manager. When i try to download I get an error

"Error downloading http://arduino.esp8266.com/versions/1.6.5-947-g39819f0/esp8266-1.6.5-947-g39819f0.zip"

I have googled and googled but cannot figure out where to find this. I am having major problems uploading even a test sketch to a feather huzzah. I have been lucky a few times, but its only works a hand full of times. mostly i just get the "error:espcomm_upload_mem failed". My googling says i need esp8266 1.6.5 but i cannot find it. Having said that, yes I have tried all the other board versions, nothing has been stable. on 2 occasions it has works, only to cause the same problems moments later.

i am using arduino 1.8.9

I think you're out of luck. The error message didn't lie. That file simply doesn't exist. The GitHub tags only go back to 2.0.0-rc1.

I really doubt that using 1.6.5-947-g39819f0 would do anything to help with your upload problem. The only reason anyone uses the old versions is because they had a feature that allowed you to do some advanced things with WiFi. That feature could used for malicious purposes and so Espressif removed it in later versions.