So you're starting a project that you're not familiar with and you barely get started and "That Little Voice" is screaming in your ear that you are about to make a huge mistake and you promptly tell that little voice to shut the "f" up because you're busy and trying to concentrate! That just happened to me and this time I'm going to listen.
I need some valve guide work done on my heads after finding out some very important info on valve guide clearance along with many other things. Thought I would just disassemble myself and bring the heads in get them fixed up and put everything back together. This is how far I got then put them back together and will bring them back to the machine shop for the upgrades. I'll let you know if the "Little Voice" was right or not.

Explain a bit more would be helpful

Refer to this thread:
First Dyno Complete

I will tell you what I tell everyone "all my projects were so easy in my head"

I cannot tell you how many times that "little voice" was right about something...

Voices

Pretty popular with the offshore crowd. Well the ones that where around for the Miami Vice days anyway.

This:

Actually the "little voice" in my head has been drowned out by the screaming!

Trust your gut

Good luck with the guide clearance !!

Where are you located?