I think with the OD I will gain some MPG at higher speeds, mabey another 2 mpg I am hopeing.

My theory on the 408 is with a .69 OD it will consume the same amount of air/fuel mix as a 281 inch motor set up like mine without OD so you might get a touch better MPG with a very mild 408 and an OD. My stroker that I will build when I get time and money will be a 416 and with mag heads and whatever I learn from this combo I should still get high 20s with the OD.

I just heard from the driveshaft shop and they said my shaft is trash and they want $230 to make me a new one. It might be sitting for a while