what are the pros and cons of each.

 

internal cant flow as much.. thats about it I guess..

 

internal sucks. external is harder to install.

 

pros external: get to run a bigger dp more easily since all you do is weld to the block off flange as opposed to trying to figure something out for the cast iron wg housing. external not as likely to spike, more adjustability (springs are interchangeable), will hold more boost over all without leaking.

cons external: obviously not the cheapest route, have to have a manifold that accepts the wg, have to run a dump tube (well, if you don't want your engine bay covered in soot and risk melting wires/hoses/etc.).

i think the pro's outweight the cons

 

me too, with dual valve actuators...gotta get as close as you can to the performance of an external. damn, i want and external.

 

is there a way to convert from internal into external?

 

yea, block off the internal passage, and install a external gate.