The only difference is the radius of the rear? radius seal? I have collected over the years a few rather nice road race pans, that were sold to me as 360 pans and I discovered recently they are 340's. They are $300+ pans and I can't find any listed new stock pans for road race any longer at Moroso, Milodon, or Canton. So anybody ever jigged up a 340 and welded in a 360 Radius? How did it go?

Maybe bolt on the pieces after carefully cutting and weld it that way for a good seal? Instead of building a jig?

I've done a 360 pan for a dakota before like that, I used the bottom of the 318 dakota pan and the top of a 360 pan, it's time consuming but not impossible.

I'm pretty sure someone makes a custom spacer for this application. Get ahold of Rick Liuzzo using the link below as he may have one or know where you can get one.

I actually "swapped" applications. Took a 318 block, and cut a piece out of the 360 pan to encompass the seal. Then made a pattern, traced onto the 318 block and cut out that piece. Swapped the "seal" pieces and gas welded them back in. My recollection is that the cutout included the rear pan bolts, but I don't remember. That (pickup) pan converted to 340/318 is still on my old Landcruiser, but I haven't run it in years.