LD4B OR LD340 FOR 273?? Coil mount?? Need pics

Thanks for the input guys. Dads 273 is for the 67 model year, which would mean heads would accept the LD4B. The heads are cast iron stock, with the new comp springs, no machine work.

LD340 is a no-go, thanks for the info.

So Im thinking of trying to come up with a coil mount for the LD4B that would utilize the rear 2 carb mounting holes. Anyone tried this?? Or any other mounting ideas??
$$ is more than tight and I dont want to go ahead and purchase a LD4B just yet without having a plan for the coil. Also anyone see any hood clearance issues with LD4B and Eddy 1405?

Thanks!