[Rocky Rotella]

485640 is early 1972. 488945 was phased into production midyear.

[Skip Fix]

My field PVCs premature ventricular contraction-sorry. I always have to think twice which ever one I'm trying to say!

Pulled my repop out yesterday and as in the picture of the RAIVs the linkage boss is completely machined so looks like a original Pontiac

[Old Goat Racer]

Originally Posted by Rocky Rotella

485640 is early 1972. 488945 was phased into production midyear.

Thanks. I have 2 of those intakes but could never find the 640 # in any books.

['ol Pinion head]

From buying & selling quite a few '72 HO intakes over the years, nice condition original '72 HO intakes with the various '71 & '72 cast dates have always brought more than the later service replacements. 2 of the SR's I've had were dated '77... batch dating had to be after that.

[Robert Williams]

Originally Posted by Old Goat Racer

If this question has been answered my intake has 485640 with a date code of 7-30-71
Is it a 72 ?

My book shows the 485640 is a non production intake. It was cast in 1971 for the 1973 455 Super Duty engine. These were not installed on the SD engines as they built the engines with cast iron intakes. I think you have a rare one there most likely out of the engineering lab.

[Rocky Rotella]

Lots of rumors about 485640 and its origin, but I heard a new Firebird book coming to market next spring has the answer!

[The Boss]

Originally Posted by Robert Williams

My book shows the 485640 is a non production intake. It was cast in 1971 for the 1973 455 Super Duty engine. These were not installed on the SD engines as they built the engines with cast iron intakes. I think you have a rare one there most likely out of the engineering lab.

This is how problems start.....no! Although these were considered for the SD program the inventory was used up in 1972 production and cars as late as December (possibly later) received the 640 intakes.

[Robert Williams]

Originally Posted by The Boss

This is how problems start.....no! Although these were considered for the SD program the inventory was used up in 1972 production and cars as late as December (possibly later) received the 640 intakes.

No problem, read Pete McCarthy's book Pontiac Musclecar Performance page # 18...

[psw]

Well the manifold pictured in post #1 is not the same as either of the ones shown in post #8...several slight differences.

[psw]

Oops, responded before realizing I had not read through all the posts yet, never mind...

[vtxman]

Originally Posted by Rocky Rotella

Lots of rumors about 485640 and its origin, but I heard a new Firebird book coming to market next spring has the answer!

I can't wait to get my hands on this book........ first I have heard of it. Next Spring is a long time to wait.

[quicksilver97ta]

I picked up one just like it a couple of years ago and asked about it here: http://www.forums.maxperformanceinc....d.php?t=698721

I was in a hurry to put it into service as I was switching from a holley to a q-jet and this was the intake I wanted to use. When I originally posted the question and read the reply’s I ended up being under the impression that it was a repop. However, after re-reading the entire thread just now I’m still not sure as one member seemed sure it was an OTC intake. There is also a link in there to an HPP article by Rocky Rotella.

But here is why it is still not clear to me. Do the OTC intakes have a date code? The “0729” casting on the bottom of the intake is not a date format like shown in other pics (ex. 8.5.70), however, it is a batch code format. So it seems like a stretch that the “9” is 1979 (although I know other car parts can have that as a date code but I just haven’t seen it with these intakes). Also why would it have a date code cast like a batch code format but then no date code?

[The Boss]

Originally Posted by Robert Williams

No problem, read Pete McCarthy's book Pontiac Musclecar Performance page # 18...

I've read it & actually know Pete - he put new seats in & assembled a set of RA II heads for me about 20 years ago - a photo of them is in the book.

As valuable a reference as his book is, there are several errors in it - that being one of them. Unfortunately you chose to add your own twist to it

I think you have a rare one there most likely out of the engineering lab.

which is what I objected to. In a hobby where people strive to have things factually correct to a ridiculous level, your quote above is not helpful in any way.

[Skip Fix]

I bought a SR 72 HO intake in '79 from the dealer so 9 could still be a date. I always thought it was strange they only had the 60-71 crossover available then though.

[gto4me1968]

I've looked just about everywhere and can't decide on whether the 488945 manifold is supposed to be painted the same engine blue or left "aluminum" color.

Anyone have good reference material for a 1972 GTO 455HO?

[PAUL K]

Correct is painted engine color.

[Bentwheelbob]

Paint. Use a high temp manifold gray paint on the crossover and exhaust port areas prior to painting so that once the engine paint burns off you will still have a nice neutral/natural rust preventative coating.

[gto4me1968]

Thanks for the quick response...paint it is on the intake. The other items are already prepped in gray.

Now...all I need to find is the correct PQ code M40 transmission.


Thanks,
Brad

[PAUL K]

The PQ is going to be a little harder to come across. but good luck!

[gto4me1968]

Originally Posted by PAUL K

The PQ is going to be a little harder to come across. but good luck!

I'm finding that to be true...I guess very limited quantities.