swap old bb chip from 3G to new 3GS to unlock?

I have a few old 3G's and was wondering if the baseband chips were swappable with the post 2011 week whatever 3GS new chips to get to an unlock able baseband of course. Anyone tried? Buying the preprogrammed chip is a lil pricey for a phone that isn't worth too much anymore. Prob some software bricking Issue perhaps. If u know a seller that is cheap that will do too. I've tried to find info on it but can't. I have no issues with the soldering or turning a phone into a paper weight lol. Just don't want it to be for a useless endevour. The blank chips are reasonable, so if there is a way to flash an unlock able baseband on a new chip that would do as well.