#1231109 heads

I came across a set of these in my parts the other day, and was wondering what all they fit ? What CC are they ? Can they be converted to 1.750 exhaust and 2.125 intake ? Can they be used on a 72 or 73 block ? Any help is appreciated.

 

Looks Like 1969 400/430 heads.

http://www.gesslerheadporting.com/g...8464cf4d587de6d085256e47001720b1!OpenDocument

 

So are they the same cc as the 70-71-72 heads ? I guess I was thinking at least the 71-2 heads were 71cc.

 

Tim

Do you have something in mind as a project?
If so then let us know what you are thinking so we can put our 2 cents in.

Paul

 

I have a 73 block that I was kind of planning on building which I would have decked, then utilize these heads to get decent compression out of my Speed Pro L2353 pistons. I'm building a couple 72 Stage 1 cars, and don't want to deck the correct WS code blocks. Also I do have a set of the #1231786 70 heads. If they are the same cc as the #1231109, is one better than the other ? I've got a set of the TA orange crush head gaskets, will they work with either of these heads on a 73 block ?

 

According to this chart the 69 and 70 heads have 69 cc.

http://gasalley.thetumbleweeds.net/tech_archive/buick/heads.htm

There is other info on that page that will interest you.

What are you going to use for pistons on the 72 Stage 1 engines that you don't want to deck?

Paul

 

The problem with these 1109 castings are they are prone to craking in between the valve springs. The last batch I had, out of 11 heads 1 mag tested OK. If you use them make sure you plug off the oil feed hole in the block that feeds the rockers. Chris

 

I was thinking of using the L2353F pistons on any of them that I would build. I didn't really want to go with a race piston because of the expense and I'm after just mild street engines.

 

Tim.

One option would be to use a Pontiac connecting rod. I think AM&P has the modified SD 455 rods in stock. These rods are 6.625" (0.025" longer than stock) and move the piston up reducing combustion chamber volume.

 

I was also going to suggest using the Pontiac rod and is the reason why I asked about which pistons where going to be used.

The Pontiac rod is bushed for a floating pin but the Speed Pro L2353 pistons do not have grooves for pin clips and are only set up for pressed pin rods.
That is one of the reasons the Speed Pro pistons cost less than other forged pistons.

Please double check me about the bushed small end on the Pontiac rod.

Options for near zero deck clearence without having to machine the deck:

If you want to go with a forged piston use the Pontiac rod with either a Wiseco Pro Tru inverted dome piston

http://www.summitracing.com/parts/wis-pt055h4/overview/make/buick

Or the TA 1611 Spherical Dish Forged Piston.

Both of these pistons will give you right at 10:1 compression ratio with 69 cc heads, .040" head gasket.
Deck clearence will be around .020" depending on the actual deck height. Stock blocks tend to be slightly over 10.570"


If you want to use stock rods and don't mind using a Hypereutectic piston, then the KB will work really nice.
The Hypereutectic piston will allow you to use a real tight .002" piston to wall clearence, great for stock type rebuilds.
It has a CH of 2.010" so the deck clearence will be .010".
Compression ratio will be around 9.8:1

http://www.summitracing.com/parts/uem-kb357-030/overview/make/buick

In all three above piston choices you get a lot better quench than the standard round dish design.

Paul

 

You are right about the small end of the AM&P Pontiac rod being bushed. It appears the original Pontiac pin diameter is 0.980". I would suspect sufficient bushing thickness allows a hone to fit a 1.000" pin.

Eagle lists a press fit Pontiac rod that could be modified for a 1" pin along with the other required machining. But probably not an inexpensive option.

Link to Eagle Rod