Click to view attachmentI have 2 sets of pushrod tubes. Both are the same length and the diameter is the same. The large ends are identical but the small are different. Which are correct?

Should be the other way around...early 1.7's had a smaller head side tube end.

Picture added

Still the same OD?
One on the right looks damaged.

Mark is correct the 70 model 1.7 had the small head diam. Most of the heads were drilled out by the machine shops when the heads were rebuilt to accept the larger tube. You may have mixed matched heads if they are one the same engine.