Johnny, You can read them yourself in these pics. I only have one 340 left and I'm in the process of machining more 360 mag manifolds. I like to sell them in pairs 340/360 "machined" mag this way members don't have to go searching for one or the other. I will sell the 360 "machined" mag manifold by itself since they are a little easier to get. Check out the pics and you can see the 340 casting number/dates. I'm showing you the 340 and the 360 mag manifold. Both have at least 2 1/4" exhaust hole. I'm running a set just like this in my '69 Barracuda 318, P/S. P/B, A/C and they fit perfect. This particular 360 manifold (already SOLD) exits in the rear where there is plenty of room...see last pic. I'm running a 2004R overdrive so the purple adapter plate (in the pic) won't be on a normal 318 a-body.