I Don't know about on a Jag, But my vette Has a Plate between the EGR and the Manifold, about 1/2 inch thick...Requires 3 gaskets to put it all together, and is a bear to seal, but once it's all good, everything fits KEWL....
Well My Jag has a 400 SBC sitting under the bonnet (hood to us Americans) So it's basically the same as your Vette motor, and it's been through smog in December so I'm good for 2 years. After that I'll be smog exempt. BUT I still want to run the EGR anyway. After all I wouldn't want to brake any laws
The tall one ainīt that pretty but it did the job.
I think they both look great and as long as they function even better. Did you machine out the big one? I don't have the tools to do something that complex. But the bottom one is really all I'd need to make I think. If I could find an EGR with a smaller diameter top I wouldn't have to worry about it at all. But 50.00 for a new valve is a bit on the step side for the wallet so a 5.00 spacer is sounding really good right now.