How much would you pay for this 340?

You better be sure what's going on here. TRUCK oil pan.
Could also be a Van pan, I have one and the best part of it is, they are 6 Qt. pans, not 5 as in a car. I think having the "J" heads, it could be a 360. which can in the vans and trucks in the 2 BBL platform. I found many "J" heads that way. I made a comment, not seeing a head marking earlier, but retrack that now after seeing a close-up of the heads. I installed the windage tray from my 340 when installing the deep pan as in photo. You just need to use the same pick-up as in the truck or van pan.