casting number help

[setandreel]

Hey all
MERRY CHRISTMAS
can't find any info on a L6 I just picked up, the numbers I have are above the BIG GM , 473483 and stamped on the flat part right behind the dis. hole are F1017DKB
Thanks all
Mike

[Tim64]

The numbers you want are just left of the numbers above the big GM. They will consist of letters and numbners. Go to inliners.org for decoding.
Merry Christmas,
Tim

[setandreel]

Thanks Tim, but inliners don't have my numbers

[Heater63]

Is it a tall deck (292 ci, 6" side covers, offset engine mounts) or the short deck (230-250, 4" side covers, engine mounts equal on each side)?

I will look up in my book tommorrow.

[setandreel]

Yes it is a 250 just not sure of the year? I bought it to replace my 230 (its a rebuilt long block) problem is my book for a 65 230 shows a timing gear oiler and there is know where to put one on my new block, I thought the 230 and 250 blocks where the same?
thanks and MERRY CHRISTMAS
Mike

[Fred T]

The link at inliners to butlers-a1 has your number. It shows as a 73-79 250, possibly with an integral head.

To find the year, you need to find the casting date code. The casting date code is usually above the starter. There you should find a series of letters & numbers. It will look like CON 2 C24 5. Decoding this is fairly simple. The CON 2 means conveyer 2, tells where the block was cast, but doesn't concern us. The C24 5 is the date code. Letter is the month, Jan =A, Feb = B,... Next is the day of the month, followed by the last digit of the year. So C24 5 would be March 24 with a year of 1965, 1975 or 1985.

Also, if you have the integral head (intake manifold is cast as part of the head), I would recommend getting one that isn't integral. They are poor performers due to airflow. If you're just dropping in a running engine, that's one thing, but I wouldn't recommend putting any money into reworking an integral head.

Any head from this series is prone to cracking around the right front corner head bolt. I would buy one that has already been magnafluxed to inspect for cracks, if possible. It's been years since I did head work on a 250, but the last manual I looked at showed a reduced torque spec for that bolt.

[setandreel]

Thanks Fred
My intake and exhaust are bolted together and unbolt from the head, this is good I hope. The number above my starter are J148 --CON 2.
I got a good deal on this long block, everything new and checked. for $700.00
so I can't complain to much Again thank you very much and have a blessed new year
Mike

[Heater63]

Mike,

Santucci's book "Chevy I6 Power Manual" lists your 473483 block as a 250cu in made from 66-79. This block did not use an integral head (which yours is not from how you describe it)

Fred T is right on the date codes. Which, is interesting, in that if you can't tell the decade with only one digit! Your CON number is J148, so it was cast October 14, but could have been 1968 OR 1978 !! The numbers by the distributor pad give info on the exact build, compression and excessories, etc, but I don't have anything to decode that.

Hope this helped,

Heater

[setandreel]

Thanks guys
As always this site and the people are great
Mike