What can I do to make my mil spec triggers better light and smooth with  crisp and clean break. I do not want to change to aftermarket parts but I can swap springs.
I have spare parts in case something breaks in a SHTF situation and dont want to mix and match in the field.

I've had good luck with switching to JP springs and just polishing all the friction areas on the FCG. I also use a Moly grease rather than regular lube on the FCG.

You're really pigeonholing yourself here. But here goes:

Springs only: JP Spring kit
Reduced power springs wear out faster.

For the money it is damn near impossible to beat the QMS trigger:
QMS trigger

QMS trigger may be an option. maybe with a JP kit to go with it.

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REPLACE IT! I know you didn't want to hear that, but its the best solution. Case hardened parts can not be ground or stoned as that removes the tiny layer of hardened surface and one is left with junk that will quickly wear out. Simply put, standard factory triggers and LPKs suck. There is to much travel, the travel is rough, and the trigger pull weight is to high. All the basic issues of any trigger group designed for the military to make it all most impossible to discharge the rifle and even harder to hit what one is aiming at. Springs are going to do nothing for the gravel road travel one feels nor how long it takes until the break nor the rough break nor are they going to shorten the excess in reset travel. Its a bad design forced in place by being a military contract rifle. Putting a 5 pound trigger spring in will lower the pull, but it will solve none of the other problems and can even add problems (light primer strikes).

There are great after market triggers on the market which I have tried. The best one I have used and I think gets the most bang for the buck is Hiperfire (Made in the USA). Their trigger has also solved the problem of light hammer strikes. I can fire hard primers all day long and still have a 2 pound trigger pull if I want to using a Hiperfire. At $185 MSRP (less if you spend some time searching) that is a good deal on a replacement trigger that solves all the problems of the factory trigger. Hiperfire has a very clean crisp break, no reduction in hammer speed or striking force, very little take up (almost none with the 24C) and very little reset (read faster followup shots).

Save your money and time, buy an aftermarket trigger.

One of my sponsors, Hiperfire, has a phenomenal trigger that will be adjustable from 4.5-5.5 pull weight coming out later this year (december) it will have an MSRP below $100.

I agree with the below other than I used wolf 3.5 lb spring and crisp as can be with no grit.

Geissele has a G2S for 165 and it feels the same as the SSA, if your on a budget OP. i have gone to Geissele in every black rifle i own, i'm spoiled

also their Mil spec triggers as posted above are excellent if you want to stay in that realm

Got your wheels turning after you felt that TImney I see. You can do like I did on the other AR I had and run the ALG trigger with some springs without breaking the bank.

Buy the QMS and call it good. I have one in a gun. It is a much better trigger than the price would have you believe

Geissele G2S is the solution if cost is a factor. They can be had for under $140 from Trading Place Pawn and Gun and they're every bit as good as their SSA trigger as is stated above. I too have them in all my AR's...you'll be spoiled and never go back.