What size drill bit should I use on the front and rear trunnion holes on my AK-74?

#16.

That equates to approximately 11\64". If you search you'll find more detailed posts on the topic.

If you have the rivets you can use them as a reference.

Welcome to the forum

Thanks guys. I came across some info that stated the holes were 5/32. So I drilled all the holes with a 5/32 bit, all the rivets fit excepts the one longer rear trunnion rivet. So all holes need to be drilled with an 11/64 bit or just just holes in the rear trunnion using long rivets?

FWIW, I've always used a 5/32" bit. No problems so far.