First Generation Firebird
Posted By: ped Ram air 4 - 03/19/17 12:17 PM
I just saw a listing for a complete 1972 Ram air 4 455 for sale.
Posted By: oldskool Re: Ram air 4 - 03/19/17 01:01 PM
As I'm sure most here know, there is no such thing as a 1972 RA4 455. RA4 heads were never used on a 455. 455HO round port heads were used on '71-'72 455HO engines. But those heads had much larger chambers than the RA4 heads. And the 455HO cam was much smaller than the RA4 cam.

But, if the engine has good round port heads, the factory aluminum intake, original carb, and original 455HO 4-bolt main block, it's worth some serious $$.
Posted By: wovenweb Re: Ram air 4 - 03/19/17 06:28 PM
Did they use the 068 for the 455HOs or were they using the Ram Air III(744) cam?
Posted By: ped Re: Ram air 4 - 03/19/17 07:49 PM
The Craigslist listing states that is has aluminum intake & 4 bolt mains so I who guess it is a 455 HO, this is probably a legit posting. I'm thinking seriously about it, just up the road from me.
Posted By: oldskool Re: Ram air 4 - 03/19/17 08:31 PM
Originally Posted by wovenweb
Did they use the 068 for the 455HOs or were they using the Ram Air III(744) cam?


The 455HO used the 068 cam. The SD455 used the 744 grind, but the cam had a different dist drive gear.

The 744 was used in early '69 RA3 manual trans GTO's. Most all other '69 & '70 RA3 engines used the 068. So, although most Pontiac guys call the 744 the RA3 cam, it actually shares that position with the 068 cam.

And, just as the 068 was used in a lot of other engines, so the 744 was used in other engines in '66, '67 & '68.

Also, the 041, which many refer to as the RA4 cam, was also used in the '68 RA2 round port engines, but used only 1.5 ratio rockers on the '68 engine. The 041 grind was also used for an SD455 cam, but again, with a different dist drive gear. Some SD455's were tested with this cam. But, it was never released in a production car. Pontiac decided to drop back to the 744 grind, in the production engines. This dropped the factory HP rating from 310hp to 290hp.

http://www.wallaceracing.com/enginesearch4.htm

http://www.wallaceracing.com/camcode1.htm

http://www.hotrod.com/articles/pon-0505-inside-455-super-duty/

Posted By: oldskool Re: Ram air 4 - 03/19/17 09:18 PM
Originally Posted by ped
The Craigslist listing states that is has aluminum intake & 4 bolt mains so I who guess it is a 455 HO, this is probably a legit posting. I'm thinking seriously about it, just up the road from me.


The block codes for '72 455HO engines are WD, WM, YB, YE

The head number is 7F6.

http://www.wallaceracing.com/enginesearch4.htm

The '72 455HO intake # is 488945.

http://www.pontiacpower.net/numbers/intake-manifold-codes/
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