engine and head #'s

Can someone tell me what these numbers are: block=14096188/ date f290 and heads=10069286/date e250 . This motor is supposedly a ls6 crate motor from gm. How old is it? I believe it is newer. Thanks. dave

[Chevy454]

heads (14096188) = 70-71, rect, OPEN, 454 service replacement, also used on later Mark IV LS-6, LS-7

block (10068286) = 454, 90-91, 4-bolt, Mark IV, Short deck

I think you had the numbers transposed between the parts, and the number for the block is as close as I could find, but probably what you got (68 vs. 69).

Thanks Rob! A neighbor of mine has two of these that have never been installed. He said he bought them as new crate motors for his boat. Never did install them. He built stands and they have been sitting for 10-15 years. They both have the 3933163 intake also. Both are painted black. I took one valve cover off and they are definitely unrun motors. Flywheels were on them as well. Why are the heads and block #'s that far apart on a crate motor? Could these be simply 2 engines built to ls6 specs? Is that in the norm? What is the value of these engines? Thanks. dave

[Chevy454]

Dave:

Are there any stampings on the engine pad(s)? I'll check in the morning, but I *believe* that the LS6/LS7 crate engines and short blocks were stamped...seems like the LS7's got something with an X, or a Z, or something funky in there. Sounds like someone may have had a couple of short blocks and then bought the heads for them seperate. /ubbthreads/images/graemlins/dunno.gif

[CJP_69]

I believe over the counter LS-6 and LS-7 engines had a small machined area above the center of the timing cover that was stamped XAA for LS-6 and XCH for LS-7.

[JoeC]

they could be marine engines and have different number system