427 casting codes question - 435HP; IL code?

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Nov 25, 2008 | 09:20 AM

Wolfgang5150

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From: Orchard Park NY

427 casting codes question - 435HP; IL code?

Confused here. Looking at a 1968 427 block; code is 3935439 (430,435HP), but the suffix is stamped 'IL', which matches up to a 390HP manual trans.
Shouldn't the suffix be 'IM', or 'IR'?
Thanks in advance.
Kevin S.
Orchard Park, NY

Nov 25, 2008 | 09:22 AM

Wolfgang5150

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From: Orchard Park NY

Nevermind; just realized it's a 1969 block........
too many damn numbers....

Nov 25, 2008 | 11:01 AM

Wolfgang5150

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From: Orchard Park NY

Or is it? Need some help.
Here are the codes:
Block 3935439
Heads 3931063
Suffix T07I6IL

And if it is a 68, how do you explain the 'IL' code on a 439 block?

I'm losing my mind with all these codes & numbers floating around.....
Thanks in advance.
Kevin S.
Orchard Park, NY

Nov 25, 2008 | 11:20 AM

wfo76

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From: MS

My pocket NCRS guide shows the 3935439 block used (late) with all 68 big block engines

Suffixes
- IL (390hp 4-spd)
- IQ (390hp auto)
- IM (400hp 4-spd)
- IO (400hp auto)

The 3931063 heads it shows as 69 390/400hp heads.

Do you have a 390 or 400hp car?

Last edited by wfo76; Nov 25, 2008 at 11:23 AM.

Nov 25, 2008 | 12:28 PM

FrankVincent

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Quote:

Originally Posted by Wolfgang5150

Or is it? Need some help.
Here are the codes:
Block 3935439
Heads 3931063
Suffix T07I6IL

And if it is a 68, how do you explain the 'IL' code on a 439 block?
Orchard Park, NY

3935439 = late1968/early1969 427/390hp (2 bolt) or 400/435/430hp (4 bolt).

3931063 = 1969 427/390 or 400hp heads

T0716IL = Tonawanda, July 16, 1968, 427/390/QuadJet/4speed

--------------------------------

the casting number does not determine the HP. You can check the dates on the block (passenger side, starter area) and the dates of the heads to confirm ... the heads appear to be replacement.

Last edited by FrankVincent; Nov 25, 2008 at 12:32 PM.

Nov 25, 2008 | 01:51 PM

Wolfgang5150

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From: Orchard Park NY

Thanks!! Great info - (I live about 10 miles away from the Tonawanda plant; wonder if there's any old parts lying around!)
Kevin S.
Orchard Park, NY

Nov 25, 2008 | 02:57 PM

FrankVincent

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Quote:

Originally Posted by Wolfgang5150

Thanks!! Great info - (I live about 10 miles away from the Tonawanda plant; wonder if there's any old parts lying around!)
Kevin S.
Orchard Park, NY

after some further research, you should also know that some late 1968 engines had those heads, so they may be original. Check the casting date to confirm ... if the heads casting date is before July 16, they are probably original to the block.

additionally, there should be a partial VIN on the pad, right next to the build date. Is it there??

Last edited by FrankVincent; Nov 25, 2008 at 03:01 PM.