Springfield ILS swap

[sparrow]

I would like to swap my ILS mainspring housing with a S&A unit...I have the MSH...do I need any other parts or will the factory internals work?. It is supposed to be a quick job and I would rather not tie the gun up at a shop if it can be avoided. Anyone have experience with this.

TIA

 

[1851 Navy]

As far as I know, you'll still need a new spring and plunger, and possibly the retaining pin too.