My 1995 Buick Park Avenue Ultra originally came with the 3.8 liter supercharged motor, which, at 267,000 miles, a lifter ate the cam and decommissioned the old car.

Well, I got a junkyard motor and the junkyard guy stated it came out of a 1995 Buick Riviera, supercharged, VIN 1, like mine. Well, I put it in and it ran horribly. Come to find out, it was the supercharger. Pulled that off and the gasket was only half there, and in such a way that it'* almost as if someone just ripped the blower/intake from a different motor and put it on this one....

I'm curious now. How can you tell if the motor/heads is a N/A motor or a */C motor? Anything specific, like rocker arms or any castings? It'* in the car right now, so I can't disassemble it, I just want a "quick and dirty" way of seeing if the block really is what the guy told me it is.

Thanks guys,
-Steve

not as easy as all that. the n/a engine is alot different. they may have bolted a different */c on yours and not been careful with the gaskets and that

Is the VIN stamped on the engine block?

Being a 95, I doubt the VIN is on the engine. At least the engines I swapped out of my car I never noticed.

It'* true, the N/A motors are a lot different. But how can I tell for sure? I didn't notice a VIN on the engine when we stuffed it in...

The primary location of the VIN derivative for the 3800 L36 engine is in the center of the LH rocker arm or LH side of the engine in the oil pan rail area of the engine. (maybe around the starter). The secondary location (1) of the VIN derivative for the 3800 L36 engine is on the engine block below the water pump but above the AC compressor.

I've seen cast #'* in those places that you speak of Roy, and I do recall seeing SERIES II stamped also. But I can't say as I have ever seen anything resembling a VIN, or a RPO.

From another source:

There are 3 locations you might find the VIN
1. The primary location of the VIN derivative for the 3800 engines is above the starter motor on the engine block.
2. The secondary location of the VIN derivative for the 3800 engines is below the water pump on the engine block.
3. The primary location of the Engine ID for the 3800 L36 and L67 engines is under the exhaust manifold close to where the bellhousing bolts to the block.
Any of these locations could be a sticker, lazer etching or a casting stamp.
The derivative is a set number that corrospond to vin characters
derivative position 1 = VIN position 3 Division
derivative position 2 = VIN position 10 Year of the car
derivative position 3 = VIN position 11 assembly plant
derivative position 4 = VIN position 12-17 the serial number on the car.

From another source:

The locations of vehicle identification numbers (VIN) vary but the following are the common places to find them:
Firewall of the vehicle
Radiator Support Bracket
Dash by windshield
Left hand inner wheel arch
Steering column
Guarantee & Maintenance Book
Machined Pad on front of engine
Drivers door or post on passenger side
Component parts as listed above -e.g.- engine, frame, etc.

Later model years most common locations of the VIN:
Left instrumentation panel
Dash plate by window
Drivers door or post
Firewall

Guess I'll start looking more the next time I pull an engine...which I hope won't be for a looooooong time.