[terry151965]

Hello
I am at a loss I found a 327 in a junkyard and am going to place it in a 1940 chevy truck on a s10 frame and when I had it cleaned the mechanist sent me the numbers off the block so I can find out more about it, and I know it is a 327 casting is # 3282870 is a 327 sbc but it has an IU suffix, which on all my research is an IU is from 427 435 hp the block and the other numbers read was FO40IU ,now is the IU strictly 427/435hp or is the IU just 435 hp. What i know is this motor had been taken out of a mid 60s grain truck. Can anybody help me with the code of FO40IU and why the suffix iu on a 327 i have not found any 327 with this suffix of IU on any of the chevy small block decoding sites.
Thanks

[vinniekq2]

only about 6 years the 327 was made,,,cheaper to make one now.try paintedjester/327nut,cobalt327,one of these members will likely answer tomorrow Hc,also
what is your question

[cobalt327]

Originally Posted by terry151965

Hello
I am at a loss I found a 327 in a junkyard and am going to place it in a 1940 chevy truck on a s10 frame and when I had it cleaned the mechanist sent me the numbers off the block so I can find out more about it, and I know it is a 327 casting is # 3282870 is a 327 sbc but it has an IU suffix, which on all my research is an IU is from 427 435 hp the block and the other numbers read was FO40IU ,now is the IU strictly 427/435hp or is the IU just 435 hp. What i know is this motor had been taken out of a mid 60s grain truck. Can anybody help me with the code of FO40IU and why the suffix iu on a 327 i have not found any 327 with this suffix of IU on any of the chevy small block decoding sites.
Thanks

Suffix IU doesn't show up in my info. That's not surprising, many truck/commercial applications aren't listed. Neither does the casting number 3282870. However, 3782870 does show up as a small journal 327, used '62-'67.

All you really need to know is it has the small journal crank, and a 4" nominal bore. It has a 2-piece rear main seal. If the oil pan is original to the engine it'll use the thin type front oil pan seal.

[terry151965]

Ater doing more reasearch on chevy commercial trucks with a block casting number of 3782870 it comes back as a 427 big block in that. that is what the IU on the suffix so it seems to be a 427/435 hp in a 3782870 block castings. after trying to run the piston numbers on the chevy i come up blank so these must be built for the 427. I sent you a link let me know what you think.
thanks. just follow the block castings




Casting Numbers

[hcompton]

I dont see the number your posted but

Here is what i can find for you. I am willing to bet the number is a 7 not a 2.

3782870
62-67
327
car & Truck 2-bolt

3782870
68-76
427
Truck Tall deck


As you can see the same casting number was used for the sbc and bbc in the 60's. Commecial applications sometimes reuse casting numbers as the tooling is already in place. I would bet its a normal 327.

Now this is not uncommon to find the block numbers and be more confused then when you started. Best thing to do from here is get the number off the crank and heads and see if they compare to the ones used on the normal 2 bolt 327. Normally with the crank and heads numbers you can figure out what you have and what type of car it was born in.

Remvoed from a 60's truck does not mean its original or even close. some engines float around from car to car for years. some get replaced a few years after the truck is purchased and the owner never looks back so no real way to tell by donor vehicle.

[cobalt327]

Originally Posted by terry151965

Ater doing more reasearch on chevy commercial trucks with a block casting number of 3782870 it comes back as a 427 big block in that. that is what the IU on the suffix so it seems to be a 427/435 hp in a 3782870 block castings. after trying to run the piston numbers on the chevy i come up blank so these must be built for the 427. I sent you a link let me know what you think.
thanks. just follow the block castings




Casting Numbers

Well is it a big block? You said it was a 327, and a BBC sure looks nothing like a SBC so it should be pretty easy to see the difference.

Most 427 BBC used in large/commercial vehicles are a tall deck. Got a photo or two?