[Held for Ransom]

Originally Posted by Kenth

Shields on valve springs were not used on 1970 Ram Air or 400 M/T #12 heads from factory.
In fact NO Ram Air heads got the shields due to stronger valve springs used on these heads.

Exactly. Which is why I called them touched (or messed with).

[Ramairnacho]

Originally Posted by Kenth

Shields on valve springs were not used on 1970 Ram Air or 400 M/T #12 heads from factory.
In fact NO Ram Air heads got the shields due to stronger valve springs used on these heads.

I read that on py that's why I asked about baffles. Are baffles considered shields? Im.still learning this stuff and trying to help other members

[johnta1]

Baffles are the long piece that covers all the springs.
The shields are the things that cover one spring and held by the spring retainer.

[unruhjonny]

Originally Posted by Ramairnacho

This topic is very controversial from all group experts. Now I believe both are correct ...

It's actually not controversial at all.

This all stems from (iirc) some 1969 RAIII engines being built with the 'L78' #62 heads;
But I believe that was only one engine code.

I have asserted before that PMD seemed to do engines in two year cycles - even though there may have been yearly casting number revision changes ect, engines for any given year will follow a pattern from one other year...
1969/1970, 1971/1972, 1973/1974, 1975/1976, 1977/1978
For 1970, you see the same stuff happening in 1969.
During the 1969 model year the 744 cam was phased out - the presence of that cam and the singular example of a Ram Air (III) having the 'L78' heads are the key differences between 1970 & 1969.

As mentioned, the engine code is key here;
Just like in 1969, the "hot ticket" was the 400-4bbl engines installed in the Tempest/Lemans & Firebird - when equipped with a manual transmission;
For 1970, that meant these cars got the better #12 heads - which is why the "RAIII" head casting was used on WT engines for 1970.

BUT!!

This WT engine thing is the exact opposite of what is being discussed;
The 1970 YZ & WS engines all recieved #12 heads.

Anyone who suggests otherwise, is either guessing, or citing a vehicle that they do not have air-tight history on.
Bad information spreads, and if someone is putting together a RAIII engine, the #13 heads can be had much cheaper than #12 heads - those heads were built in much greater numbers;
For someone to believe that the wrong head is accepted as being correct on an engine they are putting together for a car they are building is often too convenient to pass up on...