360 magnum. 1 piston lower in cylinder??

KB has some lighter pins, pn R73 IIRC, at something like 110 grams. I forget the length, may be 2.75" long instead of 3.00". I have one at home for another project that I can weigh and measure but it will be a few days. And Manley has some.

More than 5 grams from the piston may be some work. I'm gonna take 40-50 grams off of piston but that is with cutting the crown down .070", plus cutting eyebrows and some more.

I personally would lower the SCR unless the cam is large enough. I've run 10.3 and 8.3 DCR as daily driver on 93 octane. At least you will have quench to help.