I'm considering them. Are they an easy install? What needs to be removed to install them? Could I port out the stock ones myself and what would I use to do it?

To do them right you will need a welder to add metal to the front manifold for port size matching to the rear, and also to weld the rears externally.
A Dremel will be needed to gring the original internal weldsw from the rear manifold.

how prsice must the porting be, can an air digrinder be used instead of an Dremel? a dreamel would take forever i think

Put the beer down and get a dictionary.

You better not even THINK about using a dremel on those. You'll be older than VENOM by the time you're done. Even a die-grinder won't be easy.

There is no 'precise' to worry about. You grind out the factory OEM welds, nothing more. Otherwise your tubing is too thin.

I dunno, I ported the manifolds on my STE in about an hour with an air dremel....

thats what i thought but OLBlueEyes said to use a dremel, and i was thinking WTF :?

I dunno....whatever 3.1'* were. I don't think they're stainless.

I can tell you from experience, as I think I'm the only person here to ever SELF-port L27 or Series 1 L67 manifolds, you're not going to be doing any porting on them with a dremel.

CAST manifolds are a different story. It won't be easy, but a dremel will work. Cast Iron is brittle, and has very low tensile strength.

So Mr. Bill what did you use to port them with