# 455 block casting number picture



## par4n1 (Jan 28, 2010)

I will be looking for numbers on a block to confirm engine size tomorrow can someone tell me in the picture below where these 455 marks are. I looked once at this motor and saw nothing. I read where to look on different years in different locations but when i get to the actual engine I go blank. Then theres the fact of having to put all the pieces of the puzzle together and a dirty block hiding the numbers. Forget about the year made and the heads. I dont want to drive 40 miles and not know what i am loking at AGAIN ....eek :confused


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## likethat (Oct 5, 2007)

1970 they started to put on the drivers side front the engine size of the block, 350 and 455. Not sure if the 400 was stamped in 1970. Also there should be a 55 in the lifter valley for 455, 50 for 350.


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## BearGFR (Aug 25, 2008)

You need three sets of codes for a positive id.

First is the date code, on top rear center, next to the distributor hole. It'll be one alpha character followed by 3 numeric characters.

Next is the block casting code. On the rear passenger side of the block, "below" the head, next to where the transmission bolts up. It'll probably be 7 numeric digits starting with "97".

Last is the engine code, on the front passenger side of the block, just below the head. Usually two alpha characters, often starting with "W" "X" or "Y". You might also find some numeric digits immediately above or below it. They were used during the assembly-line process and don't really help to id the engine.


Cylinder heads: also have codes. A date code like the one on the block, and a casting code - usually on top of the center two exhaust ports, but not 100% of the time.

Bear


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## 68greengoat (Sep 15, 2005)

Here's a link to show various locations of codes. Halfway down the link where it shows "428" on the side of the block is the location where my 455('73) is cast.

Pontiac Engine Codes


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## par4n1 (Jan 28, 2010)

Drove to confirm the 1973 455 engine and I got numbers off block, manifold and heads and carb. The crazy thing is I havent found the first number that matches anything. I did locate the 455 on the side of the block exactly like the picture I posted. On the distributor pad were large numbers 73 so I figured that confirmed the year ( maybe not) on the front of the block next to timming chain was the number C297222 YA On the lip of the head was the number K172. The manifold around the thermostate had a number 494744 and the Rodchester carb had a copper tag on the backside that read 29865. If anyone can shed some light please let me know.


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## BearGFR (Aug 25, 2008)

par4n1 said:


> Drove to confirm the 1973 455 engine and I got numbers off block, manifold and heads and carb. The crazy thing is I havent found the first number that matches anything. I did locate the 455 on the side of the block exactly like the picture I posted. On the distributor pad were large numbers 73 so I figured that confirmed the year ( maybe not) on the front of the block next to timming chain was the number C297222 YA On the lip of the head was the number K172. The manifold around the thermostate had a number 494744 and the Rodchester carb had a copper tag on the backside that read 29865. If anyone can shed some light please let me know.


Well alrighty then... you didn't get the date code off the block, but that 73 is good enough to confirm that it's a year model 73. The K172 on the head decodes to November (K) 17, 1972 which also confirms those as being year model '73 heads (the engine plants would start casting parts for the next model year in about June or so of the previous year). The combination of knowing it's a 73 block, and a 455 (from the 455 you found) lets us determine from the YA that it's a 455 that would have been in a Firebird with an automatic transmission. The block casting code (passenger side rear, next to the transmission, should be visible if you look down behind the head on the passenger side) should be 485428. 

The heads more than likely would be code 4X (on the center exhaust ports) and would have 2.11" intakes, 1.66" exhausts, screw-in studs, with a nominal combustion chamber size of either 98 or 114 cc's.

494744 is the standard QJet intake manifold for 1973.

If the motor is sound, it's a great base to start with.

Bear


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## par4n1 (Jan 28, 2010)

Bear you are the Man. I enjoy reading all your posts. You are an asset to this forum.

So we can somewhat assume their is nothing too special about this block or heads. It's not a rare HO or super Duty but thats ok is a nice 455. I will just buy it and look for all the numbers when its in my posession. Do you have an opinion on 2 or four bolt main? Oh yea lasty I bought my 68 tilt steering column from this same fellow who has the engine. He told me he would sell me a 68 cutless 12 bolt rear, non posi for 200 Wadda ya think?


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## BearGFR (Aug 25, 2008)

Not a rare engine but built with the right parts, it'll definitely plant a smile on your face. In Pontiacs, 4-bolt mains are "nice" but not really needed until you're somewhere on the north side of 600-650 HP. When a really strong 455 block "fails", it usually splits right up the middle through the main webs, but again that's not a danger until you're REALLY making some serious power, turning crazy RPM with one, and regularly running it very hard, like in a dedicated race car. On the street, even at 500 HP "or so" --- and properly taken care of these things will last forever.

Be careful on that "12 bolt". It may be a "Type O" 12 bolt that Oldsmobile used that has 12 bolts on the rear cover but inside is actually a 10-bolt rear (10 bolts holding on the ring gear) that's not really any stronger than your garden variety GM 10-bolt - plus since they were only used in Oldsmobile A-body cars, parts for them can be VERY hard to find.

Bear


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## par4n1 (Jan 28, 2010)

We all like pictures so here are a few of new 455 and turbo 400 i picked up this morning. Bear you hit it on the head all my casting numbers are just as you thought

The block casting code (passenger side rear, next to the transmission, should be visible if you look down behind the head on the passenger side) should be 485428. 

The heads more than likely would be code 4X (on the center exhaust ports) and would have 2.11" intakes, 1.66" exhausts, screw-in studs, with a nominal combustion chamber size of either 98 or 114 cc's.


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## Rukee (Feb 8, 2007)

Nice and complete! :cheers


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## BearGFR (Aug 25, 2008)

Awesome... so get that thing in something and fire it up so we can hear it RUN! :cheers

Bear


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