Here is another shot of a closed chamber head.
Just enough of a pocket for the valves.
69 YD 400 2bbl Automatic Full size car application is your block code , yes.
Catalina and very basic models of full size.
Lowest 400 on the totem pole.
But all 9790071 blocks are identical regardless of their stamp code.
Exact same block as a 69 Ram3 4spd WS code rated at 366hp
The #13 heads are 1970 model only.
Yours are extremely early production in July 1969
We have seen this trend before with 1970 cast parts.
I had a complete 70 GPrix XH/13 engine and all of it had G dates
In other years a July casting would still be for that years production model.
Some things vary from one year to another.
Your intake part number was used during 2 years.
Part of 1968 & 1969
From around March 1968 ,,,, all the way through all of 1969 production.
You will just have to look at the casting date on it to determine.
With luck it might be an H date of 68 , and date correct for the car.
