magnum manifolds/340 manifolds
I sell the perfect compromise (I believe). For $320 plus shipping you get a 340 driver's manifold and a "machined" 360 magnum passenger manifold. Yes they will fit perfect in your car. I machine the 360 magnum so that the exit hole matches the 340 (2 1/4") so you get very equal flow. You can find and buy your own of course but the driver 340s are hard to find and sometimes expensive. The 360 magnum, if not machined, will not flow as efficiently as the 340 driver. But it's your car so you get to decide. You can see the casting numbers in the pics. I also sell the properly flared stub down pipes and adapter flanges for both manifolds, something you're going to have to buy and/or get made by someone. The 340 driver requires a very tight turn just above the torsion bar (see pic) and because of member's requests I have started making and selling this special piece (see pics). I only use mandrel bent tight radius pipe for this piece, something you can't get at the local muffler shop.
But I understand some members like to find their own parts at the parts yards so there you have the casting numbers you were looking for.
Pics are of my '69 Barracuda, 318 A Body. Good Luck, if you want more info simply ask......
treblig