605 block,..no 605 in the valley

[bison]

Working here on the Wife's 98 new truck.
I took the S intake off today in order to swap it out with an F,..to my surprize there was no 506 casted in the valley,engine is AFAIAC a 506 cause of the valley mount OPS.
Engine appears original.A history check did not list an engine replacement but that don't mean it never happened.
What do you think?

Another thing i noticed was the absense of the injector line clamps under the intake plenum bolts.The studs have a flanged nut i had not seen before on any other intake plenum bolt.
The inj lines have a rectangular plastic snap together clip holding the 2 lines pared up in place of the angle clamps.
Was this just an update or?

 

[ak diesel driver]

my 96 has the square line clamps

 

[bison]

Found a number back on the bell housing flange kitty corner of the valley.
Julian date perhaps?,#..12555506,..can one of you date that?

 

[bison]

my 96 has the square line clamps

Hmm,i learn something new every day.

 

[THEFERMANATOR]

GM cast 506 blocks do not have th raised 506 in the valley from what I have seen. The updated castings have it, but have yet to see a GM block with it for a 506. And the intake valley mounted oil pressure sensor started in 96 with the 141 block.

 

[matuva]

Found a number back on the bell housing flange kitty corner of the valley.
Julian date perhaps?,#..12555506,..can one of you date that?

so, Simon, you may have a 506

See there, post #8

 

[ak diesel driver]

http://www.thetruckstop.us/forum/showthread.php?36032-506-block here's mine

 

[chevyCowboy]

mine in my 00 is the same way it is a 506 block. the number that you posted is the actuall casting number.
On the passanger side of the motor same location as the number you posted will be the date code. here is a pic of what mine looks like

The date code in the pic translates to oct 20 99

 

[bison]

http://www.thetruckstop.us/forum/showthread.php?36032-506-block here's mine

Les, you got the same # on that block as on mine,

And what's more,i just checked....my 2 506 China blocks have that same number 12555506 on the rear and no 506 in the valley.

That raises some interesting questions,....doesn't it?

 

[NVW]

It's probably just the entire casting number. I bet your date codes are different.

 

[ak diesel driver]

I thought the first half of the number was the date code?

 

[NVW]

The bottom pic of post 5 is the date code IIRC, they contain a letter.

 

[chevyCowboy]

correct the letter relates to the month A= Jan, B= Feb, and so on the next 2 numbers are the date in that month, and the last is the year
this one reads march, 7th 94

 

[THEFERMANATOR]

Les, you got the same # on that block as on mine,

And what's more,i just checked....my 2 506 China blocks have that same number 12555506 on the rear and no 506 in the valley.

That raises some interesting questions,....doesn't it?

The chinese blocks are DIRECT copies of the last GM castings. They do not have the 506 in the valley, but do have the 506 on the rear drivers side casting just like GM's last blocks did.

 

[bison]

]The chinese blocks are DIRECT copies of the last GM castings. [/B]They do not have the 506 in the valley, but do have the 506 on the rear drivers side casting just like GM's last blocks did.

There's a few Chinese versions around,at least one of them has the 506 in the valley.

 

[mxracer14]

So if my number is 12555506 and i have 506 in the valley with the date code of H087 does that mean its an upgraded block? Its the one i just rebuilt and it did not have oil squirters....

 

[bison]

correct the letter relates to the month A= Jan, B= Feb, and so on the next 2 numbers are the date in that month, and the last is the year
this one reads march, 7th 94
View attachment 35998

Code on one of my china blocks read B170--so,..febr 17- 2000 right?

 

[1999gmc]

So if my number is 12555506 and i have 506 in the valley with the date code of H087 does that mean its an upgraded block? Its the one i just rebuilt and it did not have oil squirters....

Was wondering the same thing. I know the engine in my truck has 506 in the valley. And I just looked at a long block I acquired and it has 506 in the valley, 125555506, E148. So I'm thinking that is a 98 block? Dealer history wise, my engine has never been replaced and I bought the truck with 99K on it. That would be sweet if I don't have one of the weaker blocks.

 

[chevyCowboy]

So if my number is 12555506 and i have 506 in the valley with the date code of H087 does that mean its an upgraded block? Its the one i just rebuilt and it did not have oil squirters....

not sure on that never heard of a 506 with no squirts

Code on one of my china blocks read B170--so,..febr 17- 2000 right?

correct ASFAIK 99 was the last of the castings done by GM after that they went to Navstar, so "some" china blocks have a date code past 99 and dont have the double diamonds

Was wondering the same thing. I know the engine in my truck has 506 in the valley. And I just looked at a long block I acquired and it has 506 in the valley, 125555506, E148. So I'm thinking that is a 98 block? Dealer history wise, my engine has never been replaced and I bought the truck with 99K on it. That would be sweet if I don't have one of the weaker blocks.

Right thats a may 14 1998 block

 

[THEFERMANATOR]

not sure on that never heard of a 506 with no squirts N/A engines had no squirters in them, so yes there are 506 blocks without them.



correct ASFAIK 99 was the last of the castings done by GM after that they went to Navstar, so "some" china blocks have a date code past 99 and dont have the double diamonds



Right thats a may 14 1998 block or a 08 block

In red