borrow/ rent/ buy a borscope and a finger type recovery tool.it then turns into a claw game. I have gotten so much stuff this way. saved tons of time

 

You never know, you may find other issues by removing the head. You mentioned it is a new motor but you didn't say rebuilt, crate or simply new to you. Pulling the head will allow you a much closer inspection of the internals for only the cost of a couple of gaskets.

 

You can buy a little bore scope for like, what, 20.00 now that hooks into your smart phone.

 

yeah there are usb laptop ones that go for 15 on ebay, start there