that is the one huge misconceptions people have between the Chevy 229 V6 and the Buick 231 V6, the Easiest way to tell the difference is CHEVY has the Distributor in the Rear (like any) and in the Buick, It's in the Front.
Anyway, It took me close to 3 yrs to find a nice Buick 231 V6... Complete & Running I have gotten contact from a friend who sold his 79 Grand LeMans 4Dr to a guy in Ohio who has it now the car is PHS Documented with 54K orig miles, 1979 Buick 231 V6 (Even-Fire) with the Highly unliked TH200 Transmission which is what I'm looking for... If the Project "400hp" 231 V6 Goes south I'll go back to "basic" old school tuning... Carb/Intake & Exhaust.
The one I posted is a 1981 231 V6 with 147K on it, Supposably a VIN Model "2" Eng which was only 1979 "California Emissions" So I have yet to find out if it's actually a VIN Model "A" Which I need or a "2"... Anyway it has a POS TH350 "C" Meaning 81-87 With Electronic Lockup converter, My car doesn't have that being a 79... and the TH400 in it right now with the V8 I'm told is a "Power Sucker" And Ofc never came in the G-Bodies, But mine being a 1979 It's Technically an A-Body "78-81"