Goodman Games

I am a little confused about how to make a crawl.

Here is what I think. Please let me know if anything is incorrect.

Assuming six level 3 chars.

XP is earned as if they are level 5
CR is determined as a 3rd level party
Treasure is earned based on CR

Also I have been toying with the idea of stealing XP advances from PFS.
1 XP per dungeon level, and 3 XP to level. It comes out to about a level a crawl.
Does this sound too fast?
It basically means 17 crawls to get to level 20.

It depends on how fast you want your table to level, for one shots or pick up games faster leveling is good for a campaign a slower track may work better. With my table I'm running a campaign so they are leveling once every 6 or so crawls give or take but we are tracking time and xcrawl "seasons" so a slower leveling and tier advancement over the career was what worked for the table. Your level per crawl sounds fine if thats how your group likes to play, really there is no hard rule on how fast to level.