1970 Ram Air III manifolds.
 

Those are not true 70 RAIII manifolds. The 1970s had only 3 head flange bolt holes per side. That was the only year for this arrangement; all previous ones had 5 holes per side. Never heard of the 4 hole flanges.

Round ports
 

You thinking of round port bolt pattern for the 3? Original Round ports were 3. 4 hole for the D ports if I am not mistaken.

I was waiting for someone else to comment;

At a glance, those do not look like 1970 castings to me;
The 1970 castings have a narrowed look on the forward "tube"...
The cross section of that forward tube should be more or less triangular, where as 1969 & earlier ones were square/rectangle shaped.

I just sold a pair of NOS 1970 RAIII D-port A/F body manifolds to a PY member recently. They both had 3 holes per side. All repops have 5 holes per side.

Three bolt for sure on 1970 LH F-body