I think the 40w is too thick. Whether it will help or not, I'd drop back to the 30w. That's what they were designed for. In fact, I've had great luck with Motorcraft 5w20 semi synthetic in mine. It gets oil pressure quicker. That's the whole purpose behind these modern oils with really low viscosity cold numbers. To get oil to the engine quickly on startup and help prevent cold engine oil starvation. IMO, it also helps to run the biggest oil filter you can physically fit. I run a 2qt Motorcraft FL299 on both my slant 6 in Vixen and on my Ford 400 in Gladys. Works well. IF you can fit one in, I recommend it. Paint it black and put Mopar stickers on it if it bothers you. lol
