[BruceWilkie]

Nice find Bart. The 340 HP tripower had 4 bolt mains and had the above casting # Iirc . Also used the same head casting # except it was milled .030 at factory and had a hand stamped x on it. The 2 bolt block is virtually identical other than that.

Thick wall cast vs thin wall GM introduced @1961 these blocks also have thick deck surfaces

1960 blocks were similar except decks had revised water holes to work with the "new" non reverse cool system. 1960 heads will accommodate the gusher tubes of the 55-59 rev cool though, and can be used on pre 60 blocks.


Anyone know if 61-64 heads can accommodate the 55-59 gusher tubes???

[U47]

Originally Posted by BruceWilkie

Nice find Bart. The 340 HP tripower had 4 bolt mains and had the above casting # Iirc . Also used the same head casting # except it was milled .030 at factory and had a hand stamped x on it. The 2 bolt block is virtually identical other than that.

Thick wall cast vs thin wall GM introduced @1961 these blocks also have thick deck surfaces

1960 blocks were similar except decks had revised water holes to work with the "new" non reverse cool system. 1960 heads will accommodate the gusher tubes of the 55-59 rev cool though, and can be used on pre 60 blocks.


Anyone know if 61-64 heads can accommodate the 55-59 gusher tubes???

340 HP??

[BruceWilkie]

Originally Posted by U47

340 HP??

I stand corrected 345 HP was top option in 59(AN420). The base tripower package was 315HP ...348 hp tripowers came later.

[JD311]

My 59 motor is the same as yours, 472 "066" cam, 2brl, 10.0:1, "A" code, F 19 9 date.

[b-man]

....to get the 389 ready for storage. I did as much cleaning as I could muster before calling it good enough for now.

After a half-hearted effort at trying to separate the engine from the trans I stopped for the day. I only got as far as removing the six nuts from the flex plate to the fluid coupling through the starter hole (bottom picture), but I really don't know how to go about finishing the deed.

Any tips or words of wisdom on how to separate the two would be appreciated, I'm in uncharted waters here.

























Block casting number 532000 is now visible.



Cylinder head date codes are both the same, 'E 28 9'.



Cylinder head casting number 531395.



Timing cover casting number 532444.

[Bill Hanlon]

What is the purpose of the plumbing fitting on the left exhaust manifold?

[b-man]

Originally Posted by Bill Hanlon

What is the purpose of the plumbing fitting on the left exhaust manifold?

Please clarify.

The driver's (left) side has a sawed-off pipe stub.

Passenger (right) side has a cast iron 'Y' fitting bolted to the manifold as part of the factory single-exhaust hookup.

[BruceWilkie]

http://pontiacsafari.com/Hydramatic/1957/index.htm

Read the instructions lol ! Sounds like your almost where you need to be.

Lots of great info on that site.

BTW before my 59 AN block accidentally shipped with my 59 cat(long story)...I had chance to compare to the std cast 2 bolt I still have...other than 4 bolt caps on the AN and different casting number...nothing I could see.
My 2 bolt block was originally built as an F code...reg fuel 8.6 compression with a 4 barrel.260 or 265 HP iirc !(there is also a long story on that and how I acquired a well built 389 with no evidence it had ever run after it was built@1962)

[b-man]

Those instructions are for '56 & '57.

Do they apply to 1959 transmissions as well?

[Jack Gifford]

Originally Posted by Bill Hanlon

... What is the purpose of the plumbing fitting on the left exhaust manifold?...

I assume you mean the fitting in the center exhaust ports of the left cylinder head? Was that for heat to the bimetal spring of the automatic choke?

[Bill Hanlon]

Originally Posted by b-man

Please clarify.

I screwed up. The thing I thought was a plumbing fitting in the driver's side exhaust manifold isn't in the manifold at all, nor is it a plumbing fitting. Upon looking closer it appears to be a stud with a nut on top, screwed into the head near the center exhaust ports. And there is another one on the passenger's side head. Maybe they are just there to hold bracketry to the engine. See below in the red box.

On another note, your pictures show something that I didn't realize Pontiac kept for so long. The four holes in the side of the head are intake valve stem vents. This page from the 1957 GMC Maintenance Manual (GMCs from 1955 through 1959 used Pontiac V8 engines) has a cross-section drawing of the head showing the vent.
http://chevy.oldcarmanualproject.com...5559mm412.html

[U47]

The two head bolt/stud combination with nuts are there to attach the heat shield that's normally there to protect the P/S pump.

[Poncho60]

1960 hydro manual says in addition to what you already did, to take the weight off the rear "flywheel housing" bolts, remove those and then you should be able to remove the trans by pulling it to the rear....I assume this is the same or very close to the 59, since they are very similar designs.

[Bill Eveland]

On my 55 with the dual range I unbolted the torus from flywheel than unbolted trans from engine adapter. I set the engine trans down with the trans supported and lifted the engine off the trans they are a lot heavier than a th 350 or 400.

[U47]

Originally Posted by U47

The two head bolt/stud combination with nuts are there to attach the heat shield that's normally there to protect the P/S pump.

See shield;
http://m3.i.pbase.com/v3/09/553709/2...3.L1000125.jpg

[JD311]

Originally Posted by BruceWilkie

http://pontiacsafari.com/Hydramatic/1957/index.htm

Read the instructions lol ! Sounds like your almost where you need to be.

Lots of great info on that site.

BTW before my 59 AN block accidentally shipped with my 59 cat(long story)...I had chance to compare to the std cast 2 bolt I still have...other than 4 bolt caps on the AN and different casting number...nothing I could see.
My 2 bolt block was originally built as an F code...reg fuel 8.6 compression with a 4 barrel.260 or 265 HP iirc !(there is also a long story on that and how I acquired a well built 389 with no evidence it had ever run after it was built@1962)

I thought all 59 blocks had the same casting number?

[b-man]

Originally Posted by Bill Hanlon

I screwed up. The thing I thought was a plumbing fitting in the driver's side exhaust manifold isn't in the manifold at all, nor is it a plumbing fitting. Upon looking closer it appears to be a stud with a nut on top, screwed into the head near the center exhaust ports. And there is another one on the passenger's side head. Maybe they are just there to hold bracketry to the engine. See below in the red box.

On another note, your pictures show something that I didn't realize Pontiac kept for so long. The four holes in the side of the head are intake valve stem vents. This page from the 1957 GMC Maintenance Manual (GMCs from 1955 through 1959 used Pontiac V8 engines) has a cross-section drawing of the head showing the vent.
http://chevy.oldcarmanualproject.com...5559mm412.html

Can someone enlighten me on the purpose of these vents?

Are they somehow a pathway for small oil leaks?

[Bill Hanlon]

I don't have any Pontiac documentation supporting this, but I believe that they are there to provide a "vacuum break" along the intake valve stems, thus preventing the engine from sucking oil down the valve stem past whatever valve seal is installed.

I guess they could leak small amounts of oil that got past the intake valve stem seals.

I'll bet Jack will check in soon with an opinion.

[Jack Gifford]

I see now (one of the first pictures posted) that the long power steering pump mounting bracket used two top-studded headbolts.

[pfilean]

The little vents were to provide a vacuum break along the intake valve stem to control oil usage. As there was vacuum at that point there would not be any oil leakage out as air would be going in. That reduced the vacuum on the upper portion of the stem so it was not supposed to suck oil from the head. I've heard old mechanics say that they spent a lot of time plugging the holes as they tended to mess up the mixture some and hurt idle. Everybody complained so they were plugged and oil usage really didn't go up. As long as you have the little tin splash guards oil usage usage will be low.