SR20DET turbo elbow studs stripped? Help please

[Streamline90]

When i first got my current s13, it had a blacktop sr20 with a 3" downpipe and a test pipe to a stock exhaust. One day out of boredom decided to take stock exhaust off, and just rode around with open test pipe.

After a lot of scraping, the downpipe decided to come off. Ran open turbo elbow for a bit because i was too lazy to put the downpipe on, and i didn't have the right nuts to bolt it up.

After a search on Nico, found out the correct size for the turbo elbow studs are M10x1.5. Bought 3 of those, along with a bottle of antiseize, tried to get em in, but they would only thread in about 3 turns. After that, brought a 17mm wrench out and tried bolting them in. 2 of them are almost fully in, while 1 of them only went halfway. It took a lot of elbow grease to get them where they are.

Question is, what can i do to bolt the downpipe in correctly, without having to worry about having it leak. Should i just tough it out and get it as far as i can or what?

Need some help on this, so i can put a 3" exhaust on it.

Thanks