K-member and mount ??

Drivers side mount ears cast into the block are different from 318 to 340-360. You will have to shim the drivers side mount with an approximate 1/2" thick spacer on the back motor mount ear to mount these mounts on a 340-360 if using your existing drivers side 318 motor mount. You eill also need to get a longer bolt to go along with the spacer. Get a grade 8 as thats what the rest of the mount bolts are, or should be. Passenger side block mounting ears are in the same location and spacing for 273, 318, 340, 360. I can send you pix with a tape measure, but you have a 318 and a 340. Just measure the spacing between the fwd and aft mount ears on both blocks. The 340 block they are closer together by approx 1/2" compared to the 318.

Hope this helps
Matt