Topic: going to try to fire up an engine...

[73hutch]

i'm rebuilding a 550 from the ground up i'm not in any hurry to get it finished. i don't the history of the engine i'm going to use. the compression is good and it looks OK. should i just bolt in on, put oil in it and see what happens?

[mmtsquid]

To the extent that you can, check what can be checked - sounds like compression is OK.
Check valves and timing, make sure you have spark.
Drop the bowls off of the carbs and give them a look (especially since it's not in the frame!)
Drop the oil pan while you're at it.
If all looks well, give it a shot.