Buick 325ci specs: 3.78 x 3.622 in (96 x 92 mm) bore and stroke, shared by all 2 versions. Displacement, compression and factory ratings, plus rod ratio.
| Displacement | 325 ci |
|---|---|
| Cylinders | 8 |
| Bore | 3.780–3.780" |
| Stroke | 3.622" |
| Compression | 9.5–9.9:1 |
| Advertised power | 290–300 hp |
| Years | 2004–2007 |
| Engine | Displacement | Bore × Stroke | CR | HP |
|---|---|---|---|---|
| LH6 | 325 ci | 3.7799" × 3.622" | 9.9:1 | 300 |
| LM4 | 325 ci | 3.7795" × 3.622" | 9.5:1 | 290 |
Stroke is constant at 3.622" across the family — the displacement spread comes from bore, so these share a crank and differ in the block.
Each engine page carries rod ratio, mean piston speed, bore/stroke character and cylinder head specs where published, and links into the calculators with its dimensions already filled in.