Will a stock on a 243 Model 70 Winchester made in the SC plant….BACO model with the aluminum bedding in stock…will it fit a Model 70 made in 94 or 95 in 308 cal made in the New Haven plant. Both are synthetic stocks and 243 is stainless fluted barrel and the 308 is the stainless Classic model. Also, which stock weighs the less in each. Thought might reduce little weight in the 308 if they would interchange.

Yes; with caveats.

The barrel on the classic 308 will be featherweight contour so there will be a pretty good barrel channel gap.

The 308 will be two piece bottom metal and the 243 one piece, but you could simply leave the 243 bottom metal on and it will work.

Weight savings won’t be a whole lot; ~ 4-5 ounces for the stock.

So the 243 stock weighs 4-5 ounces less.

The difference would be in the weight of the bottom metal 2pc vs 1pc, not in stock weight.