What size bolts go on the manual tranny pan?

I want to attach the pan to the underside of my manual transmission. This is for a 71 charger with a 440 engine. I figured out what thread bolts i need but don't know the correct length. I suspect some of the holes may have dirt in them which is preventing me from a trial and error method. I looked in my manual but it only tells me the correct thread and not length.

http://www.brewersperformance.com/proddetail.asp?prod=DCB&cat=225
These are the correct bolts for the bottom cover of the bellhousing. They are 5/8" long. You can also use oil pan bolts.