SBC 350?!?!?

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Bextreme04

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Unless, like me, the 350 has been stroked to 383. Then the block number will look like a 350

I mean... its mostly immaterial to what they are trying to do here. Between the block casting number and engine stamping number, you can usually determine what the exact original application and engine model was, if it is all original. Once it has been fully rebuilt(or modified like yours) the block has usually been decked, which will remove the factory engine stamping number anyways. Once the motor has been taken down that far... there's no telling what has been done to it and you will never be able to know without fully disassembling the engine and taking measurements.
 

cstew47

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I mean... its mostly immaterial to what they are trying to do here. Between the block casting number and engine stamping number, you can usually determine what the exact original application and engine model was, if it is all original. Once it has been fully rebuilt(or modified like yours) the block has usually been decked, which will remove the factory engine stamping number anyways. Once the motor has been taken down that far... there's no telling what has been done to it and you will never be able to know without fully disassembling the engine and taking measurements.
Very good point
 

dsteelejr

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The first vehicle I ever owned was an '84 K5. This was way back in 2000 when I lived in CA and it was subject to smog checks. To pass a smog check the engine in the vehicle had to match the VIN. The VIN said it had a 305. PO swapped with a 350 because he said the 305 was gutless (later found out it was gutless because it had factory 2.73 gears). Shortly after I bought it the 350 the PO swapped blew up and my dad and I replaced it with another 350. Smog check station couldn't tell the difference. On the outside a small block is a small block. @Bextreme04 is correct, the only way to tell for sure is to tear it apart and take measurements.
 

AuroraGirl

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The first vehicle I ever owned was an '84 K5. This was way back in 2000 when I lived in CA and it was subject to smog checks. To pass a smog check the engine in the vehicle had to match the VIN. The VIN said it had a 305. PO swapped with a 350 because he said the 305 was gutless (later found out it was gutless because it had factory 2.73 gears). Shortly after I bought it the 350 the PO swapped blew up and my dad and I replaced it with another 350. Smog check station couldn't tell the difference. On the outside a small block is a small block. @Bextreme04 is correct, the only way to tell for sure is to tear it apart and take measurements.
I mean the smog station can check the vin derivative to see it’s original to the vehicle. If not original to the vehicle the code would indicate a displacement or narrow it to a few, which if the engine code dates it an entire decade back, but the emissions equipment was correct, I don’t see them questioning displacement but then it all depends on where smog test is and how motivated your smog critic is
 

AuroraGirl

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The first vehicle I ever owned was an '84 K5. This was way back in 2000 when I lived in CA and it was subject to smog checks. To pass a smog check the engine in the vehicle had to match the VIN. The VIN said it had a 305. PO swapped with a 350 because he said the 305 was gutless (later found out it was gutless because it had factory 2.73 gears). Shortly after I bought it the 350 the PO swapped blew up and my dad and I replaced it with another 350. Smog check station couldn't tell the difference. On the outside a small block is a small block. @Bextreme04 is correct, the only way to tell for sure is to tear it apart and take measurements.
Even I can laugh at the 2.73. Poor truck.
 
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dsteelejr

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Even I can laugh at the 2.73. Poot truck.

Yeah, 2.73 in any truck is a joke. I only found this out because I ended up blowing up the rear end. My uncle, who has been a lifelong (now retired) mechanic and has two squares himself, was helping me fix it and he was in disbelief when he had me count the teeth to calculate the ratio for new gears.
 

AuroraGirl

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Yeah, 2.73 in any truck is a joke. I only found this out because I ended up blowing up the rear end. My uncle, who has been a lifelong (now retired) mechanic and has two squares himself, was helping me fix it and he was in disbelief when he had me count the teeth to calculate the ratio for new gears.
Even the mall crawlers can’t use it because they inevitably slap a uneccessarily large tire on to feel bigger so the only people who could use the gear thus can’t.
 

Bextreme04

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I mean the smog station can check the vin derivative to see it’s original to the vehicle. If not original to the vehicle the code would indicate a displacement or narrow it to a few, which if the engine code dates it an entire decade back, but the emissions equipment was correct, I don’t see them questioning displacement but then it all depends on where smog test is and how motivated your smog critic is

Not all engines have a VIN derivative, and most of the ones that do are covered in grease or hidden behind accessory gears. It also doesn't prove it isn't the original engine if it doesn't have an engine stamping code, as it gets removed when the block gets decked... and rebuilding the original engine is still smog legal. If you were worried about it, you can just get the crate motor or swap motor decked and then stamp your own numbers onto the block.
 

AuroraGirl

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Not all engines have a VIN derivative, and most of the ones that do are covered in grease or hidden behind accessory gears. It also doesn't prove it isn't the original engine if it doesn't have an engine stamping code, as it gets removed when the block gets decked... and rebuilding the original engine is still smog legal. If you were worried about it, you can just get the crate motor or swap motor decked and then stamp your own numbers onto the block.
Yes I’m saying that it wouldn’t be impossible to tell but I understand that they aren’t that anal either that would be ridiculous lol
 

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Unless the OP is getting into the internals, really doesn't matter what size it is. All the externals interchange. Plugs, wires, carb, etc.

Very unlikely its a 305 or a 327 unless it was swapped in. Pretty sure 305's started in cars around '76/ 77 and in trucks in early 80's. Don't think 307's were ever in trucks but don't know for sure.

Most likely a run of the mill 350. They were the original engine in 99% of these trucks. They were cheap and plentiful during the late 70's through early 2000's when original motors were wearing out and the least expensive V8 to rebuild. Why waste time on anything else in that period?!? I worked at PAW in the 90's and we sold/ shipped 3-4 350's a day. Maybe 1-2 BBC, SBF daily, and a couple others a week. Most 262, 267, 305, 307 cores went to scrap.

If its a 400 crank, there will be a weight behind the vibration dampener unless its a high dollar race motor that's been internally balanced.

400 block, 3rd freeze plug in middle on 4 bolts, raised ridge on 2 bolts.
 

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