[Safari Larry]

Originally Posted by Bill Eveland

Any pics of the front of the block when you got the 60 cover cover off to show what was done to use that on a 59 block? I thought the reverse cooling holes had to be changed to standard but didn't really see how to do it.

Good question Bill. I've looked into converting a 60 block into a 59 reverse cooled block. I found that two holes needed to be drilled in front of block (for recirculation interface), additional holes needed to be drilled in block deck, and some holes needed to be re-centered and enlarged. Given the difficulties of doing all that and not having confidence that everything was covered, I decided not to do that and keep my 60 block cooling like it was originally designed.

Now that's not what we are talking about here, we are talking about going the other direction, going from a reverse cooled block (59) to a conventional cooled block. To do that, no change should be required at front of block for interfacing with the 60 front housing (water pump housing). The large holes in front of block are already there for pumping water directly from front housing into block. The problem is in the block deck where some holes would need to be plugged and some holes would need to be made smaller -- to make it the same as a 60 conventional flow block and force more water flow to rear of block.

[marks73ta]

I was told by the seller that he thought it was a cast iron regular '58 intake. The part number cast intot he top is 528578. It's a four barrel flat manifold.
MArk L

[tom s]

61s did not use rev cooling.The 61SD was never a complete engine.You had to buy the SD stuff aftermarket to build it from a 425A block.They used a reg 61 front cover,only diff was the heads and intake.The 389 SD used a alu tripower and a single 4 NASCAR intake.In 62 they used the 306 heads on early 62 SD engines with the 991 2-4 intake that could be used on 55-60 or 61-64 water pattern buy changing the position of the soft plug in the intake.Tom

[PRC]

Originally Posted by Safari Larry

Interesting I thought the water interface between intake and heads were different. I've heard some after-market manifolds were set up for interfacing with either 60 & earlier or 61 & later but I didn't think the Pontiac manifolds interchanged. But this wouldn't be the first time I was wrong!

That's what I thought too until a few years ago. When I bought the '61 SD intake the seller told me that it would only fit 55-59 heads and '61 SD heads. I was skeptical that a '61 intake would fit the '59 heads but I took a chance. When it arrived I placed it next to the '59 intake on a bench and it appeared identical except that the '59 was iron and the '61 SD was aluminum. It bolted on and has been running well for several years now.

In light of this, the intake on those '61 SD heads would have to be a '55-'60 or a '61 SD. I was under the impression that all of the SD intakes were aluminum so since this one is iron it must be a '55-60. Is it tri-power, dual quad, or single quad? I could not tell form any of the photos.

[mechanickeith]

Marks cast iron manifold is a single 4 bbl. Almost had to use the cherry picker to get it off!!! Man that thing is heavy!!!

[Steve Barcak]

Originally Posted by mechanickeith

Marks cast iron manifold is a single 4 bbl. Almost had to use the cherry picker to get it off!!! Man that thing is heavy!!!

still no intake pics. If it has the 2 bolt holes for the gen mount on the right side, it is '55-'58.
should also be date coded as well

Nice find Mark. How did you find it? was it n Craigs? or?

You can use that bellhousing and flywheel on your hot rod motor now too.

[mechanickeith]

Here are a couple partial shots of the manifold. Dont know why I didnt get one after it was off.

[marks73ta]

Pics of the intake.





Pic of the intake ports.



Pic of the intake side.



More pics coming.

Mark L

[marks73ta]

More pics.
Pic of the chamber.



Pic of the full head chamber side.



Pic of the exhaust ports.



Pic of the exhaust side of head.



More coming. Mark L

[marks73ta]

Pic of the Tempest timing chain.



Pic of the intake chamfer in the bore.



Pic of the sleeved no. 7 bore bottom.



Mark L

[mechanickeith]

Intake manifold # 528578,,,1958 370 manifold, according to the Wallace racing site search engine.

[marks73ta]

Well, so far much of what the seller told me has been close or correct. So maybe the rest was correct also. That's a nice change of pace hey? Mark L

[mechanickeith]

You have that thing back together & running yet????

[marks73ta]

Ready to drop into Betsy! LOL.

[mechanickeith]

Lets do it!!! She will haul a$$ then!!!

Glad you found this beast Mark!!! Very interesting old school build with history. Waiting to see what the cam specs are???
Thanks much for letting me tag along & help out!!!

[60man]

I had a set of those heads. The " Venturi " shape of intake ports always intreiqued me.
Nice score.

[marks73ta]

Hey Troy. They really are usless as far as a performance stand point but they are still a piece of Pontiac history. Someone might be looking for a pair for a restoration. They would just go to waste on my shelf.
Steve. Yes I found it on Craigslist. But I ignored it at first figuring, sure, everyone has a pair of Super Duty heads on their Pontiac motor. But then I had to go look. I'm glad I did. Mark L

[65nss4spdGTO]

Originally Posted by marks73ta

Hey Troy. They really are usless as far as a performance stand point but they are still a piece of Pontiac history. Someone might be looking for a pair for a restoration. They would just go to waste on my shelf.
Steve. Yes I found it on Craigslist. But I ignored it at first figuring, sure, everyone has a pair of Super Duty heads on their Pontiac motor. But then I had to go look. I'm glad I did. Mark L

Mark,

I didn't see it posted here, maybe I missed it. The 345HP engines that came with the long branch manifolds are casting AN Automatic / AM 3 speed if I remember correctly. The cranks were also "arma steel"

Calvin Hill
Hill Performance
708-250-7420

[marks73ta]

Calvin. The seller did say he kept the manifolds so they may have been the long branch manifolds. I never did see them though. The crank is armasteel. I can't find any stamping or raised cast marker that shows AN or AM. But are you thinking of a '69 block? This is a '59 block. The heads are 1961's.
Got so me more pics. This is the bottom of the block showing the four bolt drilling.



A comparison of the larger, stouter main caps versus a '73 400 main cap. This first one is number one mains with the '73 laying on top of the '59 cap. A lot more material on the old caps.



The same with the number 2 caps. The '73 two bolt cap on top of the number two four bolt cap.



And just a shot of the 4 bolt caps all together.



Plus the early blocks had a higher percentage of nickel in the mix so they are all that much stouter. Another reason I went with the other '60 block for my '63 Catalina.
Mark L

[65nss4spdGTO]

Mark,

We still have our original 389ci 345 HP block. Stamped AM. We also have a AN block that was removed from a auto car with the long branch manifolds. My dad was working in the shop with me today and he said, don't be surprised if the block has no stampings or just an X.????

Calvin Hill
Hill Performance
708-250-7420