[PurelyGTO68]

I would expect the 69-70 RA III to follow the same fan application convention as the 68 HO since it's basically the same engine and can be ordered with A/C.

Next interesting question for me is what fan did the 69-70 RA IV have? My MPC book doesn't appear to make any distinction for RA III or IV. I wonder if the 4 blade fan was required with the 4.33 axle?

[68pongto]

Here is car #3 on Ram Air II roll call build sheet. It also has the 34 FAN code and the 53 SPACER code. I'll add it to my chart

FAN CODE --SPACER/CLUTCH---ENGINE--- DESC.
AA-----------------PH--------------------- YS-------- 68 GTO AUTO WITH A/C
BB-----------------53----------------------WT--------68 GTO 4-SPEED NO A/C
AA-----------------PG----------------------YN--------68 LEMANS AUTO WITH A/C
34------------------53----------------------YN--------68 LEMANS AUTO NO A/C
34------------------53----------------------WY-------68 RAM AIR II GTO MAN
34------------------53----------------------XW-------68 RAM AIR II GTO AUTO

[Geoff]

It is no wonder GM gave Pontiac the chop! Ridiculous number of fans with huge inventory costs when 4 fans would have covered the whole model range.

[68pongto]

Originally Posted by PurelyGTO68

I would expect the 69-70 RA III to follow the same fan application convention as the 68 HO since it's basically the same engine and can be ordered with A/C.

Next interesting question for me is what fan did the 69-70 RA IV have? My MPC book doesn't appear to make any distinction for RA III or IV. I wonder if the 4 blade fan was required with the 4.33 axle?

I think by 69 the 4 blade fan was not used? I could be wrong. My brother's 69 RA III Judge with a WS engine has the original 5 blade flex fan. I think the 4 blade was a 67-68 thing? Another theory I have is that the wrong fans (5 blade) may have been put on some RA I and RA II car at the factory. The line workers would have been so used to non A/C GTO's that got the 5 blade flex fan that they mistakenly put the wrong fan on? I'm sure the pulley and fan selection was at the final assembly plant. The Ram Air cars would have been far and few between in 68. Just a thought.

[PurelyGTO68]

Originally Posted by 68pongto

I think by 69 the 4 blade fan was not used? I could be wrong. My brother's 69 RA III Judge with a WS engine has the original 5 blade flex fan. I think the 4 blade was a 67-68 thing? Another theory I have is that the wrong fans (5 blade) may have been put on some RA I and RA II car at the factory. The line workers would have been so used to non A/C GTO's that got the 5 blade flex fan that they mistakenly put the wrong fan on? I'm sure the pulley and fan selection was at the final assembly plant. The Ram Air cars would have been far and few between in 68. Just a thought.

Sounds reasonable that the fan designs we're improved and updated through the years since perhaps the 4 blade fan was phased out. I do see that part number in the MPC book for the 1969 V8 350 engine so that might have been the last use of that item.

Out of curiosity, I just looked at a build sheet for a 70 GTO with 455 and A/C. There isn't a box for fan but there is a box for fan clutch. Code on this particular car is "7J-PC". Looks like the fan and clutch codes we're combined by this time. Small detail but very interesting just the same. I suppose this means that by 1970 the fan spacer bin was removed from the engine dress line. If true....then by default the 5 blade flex as well as the 4 blade fans may have been discontinued around this time. By 1970....did all fans have a clutch?

On a totally unrelated topic....I find it interesting that the RPO code for A/C is "C60". Same code as my 2005 GTO.

Sent from my XT1585 using Tapatalk

['ol Pinion head]

4 blade, 5 blade var pitch, & 7 blade clutch fans continued up through the '70's on Pontiac V8's. The HDC 7 blade var pitch fan was used up through at least '71 models on non AC B series. The 5 blade var pitch fan changed part numbers 3 times. The last time, in '73, the positioning of the blades was reconfigured. Many times, there will be characters trying to sell that latest version as a correct late '60's/early '70's performance GTO usage fan, it is not correct for that. Have several of the latter 5 blade fans, several that are dated for '73-74 usage & several that date for non AC w72 Birds.

Post after post, we keep seeing reference to MPC's. One thing I've learned & have documented on numerous parts is there were occasions of alternative components being used. Let's say an 06A body built Lordstown built RAII Bird was built with a 4 blade std steel fan. Does that mean every RAII equipped Bird that was built out of Lordstown, received that 4 blade steel fan? What about the other F-body plant, or the four '68 Pontiac A-body plants? On low production combinations, often if there is a question to whatis correct for a specific build, it is best to compare to other builds out of the same assembly plant, same time of the year. Only then, can one narrow down to the most likely used component.

Here's just one good example of a rare part that that one can't believe a MPC to know the parts original usage. I've owned 5 or 6 original date usage "1941" distributors...'69 RAIV right? Pulled each one of these distributors out of their original born with blocks. Had in my hands another as I pulled it from a customers numbers matching 30,000 mile original RA4 Judge during restoration. Also have owned two SR "1941"s in the box. Not a single one of these 1941's was stamped early enough to have come out of a '68 RAII engine, though am sure we can agree that early dated 1941's were used in the RAII engines.

Of these 7 original dated 1941's, 6 of them were never installed in a ' 69 RAIV engine. Their original factory installations were in performance Dport engines built 3-4 months before the first customer avail RAIV rolled out of an assembly plant.

Can name instance after instance of similar occurrences. it's real convenient to whip out MPC's or build sheets & state emphatically, this is how the car built. That is not always a fact.