Timing Chain-moving the Crank

I think the new part will work even though the listings didn't include your 1970 318. An LA timing set is an LA timing set as far as function. It just doesn't have that adjustment feature your original set had. You just turn the crank sprocket to line up the marks and your good
The other way around... the old set did not have the adjustment feature.....

OP this chain is good for the LA 318's of all years, including yours. It is a much better chain than you had.

If you want to use it: Look at the crank sprocket; each of the slots will have a small dot just under the gear teeth between 2-1/2 and 3-1/2 teeth to the left of each slot. If you want stock cam timing, then pick the small dot that is exactly 3 teeth to the left of the nearest slot. Use that small dot at 12 o'clock and the cam sprocket dot at 6 o'clock. BTW, there should have been a paper with the chain set that told you which stamped symbol (that appears over each slot) is for 0 cam timing change or standard cam timing, for advanced timing, and for retarded timing.

Once you get it on but before putting on the timing cover, accurately lay a straight edge from the center of the cam bolt to the center of the hole in the crank; those dots should line up along that edge. It is a good check on you eyeballing the dot-to-dot alignment.

Use some lock-tite on the cam bolt after cleaning the oil off and cleaning the oil out of the cam snout hole, and make sure you torque that cam sprocket bolt to spec.