I looked at the Wilson sight.. They list a number 20 spring for it. I know some run 18's ... Ive new to the tuning up of 1911's. Also does an extractor need tuning or is it normally a drop in part?  I was wanting to change at least the recoil spring and ( firing pin spring with a heavier type )... Seems a lot of folks do that. Its a 1971 light weight .. I have no history of springs ever being change. Pawn shop buy. I thought it would be good to change them out before I go shooting. Main spring hard to change out with out me screwing up the pistol ????  I take it Wilson is as good as any ones elses brand of springs and parts..... ? Thanks WarDawg

search wolff gunspring they sell what you need.

If you not having extraction issues do not change or tweak your extractor.  The Colt extractor is a quailty part and does not need to be changed.

Mainspring I've never had to replace one due to light primer strikes or anyother problem, some have close to 40,000 cycles on them if not more.

Wolff gives you a firing pin spring with each purchase of a recoil spring. Wolff has the numbers listed for Commanders, I go with etra power one just becuase you have a Al frame, but a normal one will be just fine.

18lb is stock.  You can change to 20, but it isnt really necessary.  YMMV
I would definitely change the springs though

An extractor would need to be tuned.

Mainsprings are easy to change out too if you can detail strip your pistol.
There are videos on how to do it.  IIRC there are a few from brownells or another well known name

Wolff springs are also GTG

If you can find them there is a small buffer that fits on the recoile spring guide that will reduce shock transfer to the frame.  I can't recall if it was delrin or not but I think it was some kind of polymer.  The old Lightweight Commanders would crack but it was after many thousands of rounds so very few wore out to that poiint.