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ram air what??
is there a definitive glossary of years, block codes, transmissions and head codes that covers 1967-1970 pontiac ram air options for GTO and firebird?
i have not found anything all encompassing for the "glory years, of ram air." i do not want to argue the 62s were ram air 3s, but fir starters: 1967 ram air "0", cold air induction available on gto and firebird? same 670 heads, different block codes? 1968 ram air "1" avaialable gtos and firebirds, cold air package and differnet heads, 31s? no 16 dports were ram air? 16s with an open air option were HO, ram air option but not ram air 3? later 1968 ram air II, 96 heads, cold air package, different block codes for a body and f body 1969 ram air III, 48 d ports on both transmissions? cold air package, different block codes for a body and f body 1969 ram air iv, 722 round ports cold air package, not required but available, different block codes for a body and f body 1970 ram air III d ports? cold air package, different block codes for a body and f body 1970 ram air IV 614 round ports cold air package, not required, but available? different block codes for a body and f body |
To me, Ram Air was more of a hood-air cleaner option, except the RA II heads were cast R 96 A.
I mean 421 HO & 428 HO with Long Branch, and 70 455 HO are strong. Making D-Ports highly ranked. |
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you are mixing things a smidge by using non-PMD terminology.
To answer your query succinctly, it is generally accepted that Pete McCarthy's book entitled 'Pontiac Musclecar Performance 1955-1979' is the "Pontiac bible"; This book lists all the block codes, head castings, and camshafts - cross referenced to the factory horsepower values (which was typically the indicator of the engine type). Pete's book does cover differences for heads like the 667's which were assembled differently for non-RA vs RA engines. Pete's book does have some omissions, and I have been given by another enthusiast, pages which address some oversights... Ames sells this book - HERE is a direct link to their page for it. Also, Rocky Rotella updated his "How to rebuild Pontiac V-8s" book, and added an appendix which covers much of the 1967-1979 Pontiac engine codes ect. This book is Cartech book SA200 and is ISBN 978-1-61325-563-6 But to the "Ram Air" designations; (I am touching on this because your post assets "Ram Air 0", and block codes differing where they do not.) Pontiac Motor Division terminology: 1965 (no 'Ram Air' engine offered; an over the counter 'ram air' air cleaner set up was offered) 1966 Ram Air (late model year; tri-power engine; engine code 'XS') 1967 Ram Air 1968 Ram Air (D-port) 1968 Ram Air (round-port) 1969 Ram Air (D-port) 1969 Ram Air IV (round-port) 1970 Ram Air 1970 Ram Air IV (round-port) 1970 Ram Air V (round port; non-production; different design heads and cam) The "Ram Air I", "Ram Air II", and "Ram Air III" are designations that enthusiasts used after the fact. |
ok so that does clear it up. does that mean that no factory cars had ram air III or ram air iv stickers on the hoods, from the factory?
pontiac must have counted 3 other versions to get to 4? |
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As far as I know, only Ram Air IV A body cars got the hood decals saying it was a RA IV. RA 3 cars got a decal saying "Ram Air"
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Oh my, this could be a long thread...
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Gary in post 7 is correct.
The ram air and RA4 name was given by the factory, not us enthusiasts. |
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As far as I can recall, the option wasn't called anything other than 'Ram Air' or RPO L67 anywhere for public consumption - only for some insider bulletins. Even MPC's refer to them as 'Ram Air', and use engine stamped codes to identify which version. As such, any previous unfulfilled orders for 1968 'Ram Air (I)' cars were fulfilled as 'Ram Air (II)' cars - as the RPO was updated (or maybe you want to say it was replaced?). I might be a bit off here, so I am open to correction; Weather or not the 'Ram Air II' or 'Ram Air Two' (bulletin 68-13) were used for the average customer or not, the 'Ram Air I' and Ram Air III' were not. For those who don't know the "IV" came about because of the intended (air cleaner) intake configuration (four sources of incoming air); The I, II, III, & IV just work as an easy way to summarize the progression, but if you look at this from another angle, there were in essence three different configurations: 1st) D-port heads; cast iron intake; 744 cam w/67cc heads 2nd) Round port heads; cast iron intake; 041 cam w/67cc heads 3rd) Round port heads; aluminum intake; 041 cam w/67cc heads Up to the beginning of the 1969 model year, all these engines used the same RPO L67. Over time, that "67cc" (a nominal number I am using) became rolled into "72cc"; That "72cc" number came about to summarize many of the 67-70 high compression heads - but posts on this very forum have shown that the non-RA large valve heads tended to be often around 78cc, while the smaller combustion chamber heads were around 67cc. 667(RA) / 997 = 67cc 31 = 67cc 48 = 67cc 12 = 67cc (R)96(A) = 67cc 722 = 67cc 614 = 67cc (please bear with me for another moment) With that being said, the 67cc heads appeared to be a pre-requisite part of any Ram Air engine; I say that in ever facet of life, there are exceptions to every rule - in this example that exception are the few 1969 automatic backed L74 cars which had the larger chambered 62 heads. As I see it, the 1969-RAIII was in essence a re-boot of the D-port RAI for the 1969 model year. Prior to 1969 RPO L74 was used for the 400HO; IIRC early in the 1969 model year RPO L74 was being referred to as the 400HO - if I have this (somewhat confusing) information straight, the "400HO" was dropped when the 'ram air' induction became a part of the standard equipment with the L74 engine option. The 1969-L74 engine started out with the 67cc (#48) heads, and a 744 cam (downgraded to 068 when backed by an automatic), but later in the year, all these engines received the 068 cam; If I have it straight, by the time the 744 cam was removed from L74 engines, PMD was using the title of 'Ram Air' with this engine option. Engine options were in essence carried forward from the late 1969 model year verbiage into the 1970 model year. |
sorry - again I'm trying to be helpful here:
If my info is straight, four bolt mains should be addressed. I believe that early 1967 L67 engines had two bolt mains, but four bolt mains were phased in when a new block casting was made which accommodated four bolt mains. All 1968 L67 blocks had four bolt mains. All RAIV blocks had four bolt mains. I have understood that most RAIII engines also had four bolt mains, but not all did. I seem to recall reading contradicting information, but my understanding at this point is that for 1969, it's something of a crap-shoot if your L74 has four bolt mains. While for 1970, unless it was an automatic backed L74, you are almost guaranteed four bolt mains. 1969/1970 L74/auto = YZ 1969/1970 L74/mt = WS Bonus info: almost all 1970 model year blocks were drilled and tapped for four bolt mains; Aside from RAIV & RAIII blocks, some s/t 400 blocks (code WT) recieved for bolt caps. |
Also just for the record only the the 68 1/2 and up round exh port heads had forged pistons.
No D port head ever did. |
so in summary, it takes 4 bolt mains, 67 cc heads, forged pistons, and fresh air intake system?
ram air 4 is ram air 4 due to the number of fresh air entries into the induction system? a fresh air system on 67 and 68 firebirds and gtos, did not have 4 points of entry? but not every ram air 4 headed car had a fresh air system? for the record i have never had a real ram air thats why im asking, im prob doing a tribute with my 68 however. |
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This is a short block assembly difference. Although you are technically correct, I believe you are mistaken to a point. Like you, I have understood that before the 1968.5 L67 (RAII) all short blocks used a cast piston; For 1969 & 1970 L67 short blocks continued to use forged pistons. IIRC the only other factory installed PMD short blocks to use forged (TRW) slugs were the 73-74 SD455. Where you are technically incorrect, is that some 1970 L74 engines were assembled using the same short block as the L67/RAIV engines. |
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There's a reason PMD didn't require four bolt mains or forged slugs for the D-port engines. The key component is the intake setup - if you have a nice GTO, I doubt anyone is going to fault you for adding a RA setup to the car. I would suggest the key parts are intake setup and exhaust manifolds. Second to that would be camshaft selection - I would expect that many owners of D-port RA cars are probably not running factory grind camshafts. To further answer you, the 1968 & earlier ram air system was essentially an air cleaner that sealed to the hood with no controls, but on some applications block offs could be installed along with regular air cleaners for inclement weather use (the RA induction and cast open hood scoops were included in the truck, to be installed after delivery - regular closed hood scoops were installed on the assembly line, along with a regular air cleaner assemblies). The 1969 GTO & Firebird, as well as the 1970 GTO RAIV system had a driver operated cable to control where the inlet air was coming from. I believe that the 1969 RAIV setup ended up being used on all 1969 RAIII cars, but I could be mistaken. The magazine 'High Performance Pontiac' (RIP) had a neat article on the still born 1970 LS1, and offered a feasible explanation as to why the RAIV engine saw such a lengthy delay on the Firebird - only to be the same engine that the GTO used... which carried RPO L67. HERE is a short online article showing many of air induction setups. HERE is another article, if any of these posts were a bit too confusing. As is often the case, this second article is mistaken, as the 'Ram AIr' engine option was a distinct thing as early as 1966 - where as the article suggests it wasn't until 1968. If this Haggerty article was correct, there would have been no need for PMD to differentiate the revised RPO L67 as 'Ram Air II' or 'Ram Air Two' for insider bulletins. |
I have taken apart two original 1970 what we call RAIII motors and they had non forged pistons.
I am sure there have been the odd ball stuff like when we have seen 4 bolt mains in a service replacement block for a warranty on a 2 bbl motor because that’s all that was in inventory at that time to send to a dealer. So it would follow that if an under warranty 69 or 70 RAIII motor was in need of a service replacement block that it could have got a block for a RA4 motor with its forged pistons. Keep in mind the only way Pontiac provided blocks where with just pistons and rings , no short block assembly’s could be had. |
no.
my mentioning of L74 engines (WS or YZ) being built from L67 short blocks has been mentioned on this very site as being a documented fact. The L74 short block (and all lesser 400's for 1970) used a 9799914 casting, while the L67 used a 9799915; The 915 is actually a modified 914 block - iirc it has been asserted here that the "5" indicated forged pistons in the short block assembly. To state this another way, there are documented L74 engine assemblies which had utilized 915 shortblocks. |
Thata a trick question!
There was no ra1. O here we go! |
What about 400 SD blocks vs ra4 in 70.
And 4 bolt ra3s? My guess under cover ops!;) |
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OG to the car 69 WS RAIII block, drilled for 4 bolt but came w/ 2 bolt caps.
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