Do you have to send in the head for the fire ring kit or just the o ring kit. is the fire ring kit a big help. It seems like its for keeping the head on. Could someone educate me. I want to know if I should go all out and do the head or will the fire rings be enough. I have so much stuff done to the motor Id rather not do the head unless it makes a huge difference. thank you.

 

Yes and Yes.
Do a search theres tons of reading on it in the 2nd gen performance section.

Whats a 650 DD clutch?

 

650hp Dual Disc clutch

 

Really the way to identify the clutches is by their plate load, puck material and puck count (if your talking about a South Bend).

 

How does that work. Yes its a south bend.

 

Read post #4...Looks like you got it figured out