[johnta1]

Where you are technically incorrect, is that some 1970 L74 engines were assembled using the same short block as the L67/RAIV engines.

This should be that some WS coded engines used the 9799915 BLOCK but still had cast pistons. These blocks were also ground off '4' and stamped '5' in its place. (also had the 068 cam in it)
These also seem to have been in the Judge and not TA?

[unruhjonny]

Originally Posted by johnta1

This should be that some WS coded engines used the 9799915 BLOCK but still had cast pistons. These blocks were also ground off '4' and stamped '5' in its place. (also had the 068 cam in it)
These also seem to have been in the Judge and not TA?

huh... I thought I read quite the opposite.

[johnta1]

Not for the RA III engines. Why they used the 979991'5' block for some RA III is unknown as far as I know.
They also seemed to be from Hxx9 to Jxx9 cast blcoks. Possibly they had an excess of 915 blacks and used them for the WS/YZ engines. I have one of those blocks that came out of my 70 Judge. It had all the parts of a normal WS engine, cast pistons and 068 cam.

I would say the 'recipe' for the engine makeup is based on the WS/YZ codes and not on the 9799914/15 block.

BTW, if bought over the counter, the RA III would still have the cast pistons.

[73T/A]

The name Ram Air III gets used often in describing 69-70 Judges and Trans Ams with D port engine.Did Pontiac officially ever use this name in sales brochures or marketing material to designate this particular engine or was just adopted by the general public.If we compare a a standard 1970 GTO 350 HP 400 WT code engine to the so called Ram Air III engine the only real differences are the Ram Air exhaust manifolds and the functional air breather.Both engines use the same number 12 cylinder heads and intake manifold.Also both engines use the O68 camshaft.

[unruhjonny]

Originally Posted by 73T/A

...If we compare a a standard 1970 GTO 350 HP 400 WT code engine to the so called Ram Air III engine the only real differences are the Ram Air exhaust manifolds and the functional air breather.Both engines use the same number 12 cylinder heads and intake manifold.Also both engines use the O68 camshaft.

Sorry, you are mistaken.

WT(L78) to WS(L74) differ by:
Camshaft: WS 068 / WT 067
Carburetor: WS 7040273('573-CA) / WT 7040263('563-CA)
Exhaust manifolds: WS 'ram air' castings / WT 'standard' castings
blocks: WS* 4-bolt mains / WT* 2-bolt mains (* = this was how it was supposed to be)

Actually as I have read and understood it, PMD did a service to people who ordered the standard 400-4bbl in the A & F bodies;
I believe I read it described as "this years hot ticket" or something to that effect;
PMD said to have intentionally put the "hot" (D-port) Ram Air heads on these engines.

As a point of comparison, for 1969 the L78 did NOT share heads with the L74.

[73T/A]

Not mistaken on the exhaust manifolds.I mentioned that one of the differences was the Ram Air exhaust manifold's.Looking at Pete McCarthy’s book he list the 1970 GTO engine(WT) with manual transmission getting the 068 camshaft.He shows the automatic equipped GTO getting the 067 camshaft.