Hey all
just got the numbers from the front of my block, Its a YJ block with the numbers 243176 above the YJ, can anybody help figure out what this engine is??? Can't find this block info anywhere i look.. thanks
Nick

http://www.classicalpontiac.com/cgis/engine.cgi
http://www.wallaceracing.com/cgi-bin/engine3.cgi
http://userweb.suscom.net/~jasonrogers/engcodes.htm
http://www.teufert.net/pontiac/engcodes.htm

You need to find the casting # and date. Some possibilities:

Horsepower
Cubic Inches
Trans
Code
yj Compression
Cam
Heads
Carb
Year

356 421 A YJ 10.75 67 77 3X2 65
356 421 A YJ 10.75 67 93 3X2 66
250 326 A YJ 9.2 254 140 2 67
265 350 A YJ 9.2 254 17 2 68
265 350 A YJ 9.2 254 47 2 69
190 400 A YJ,YK 8 255 4X 2 74
170 400 A YJ,X4 7.6 255 6X 2 76

YJ looks to be a 1968 or 1969 350. Like Vikki says, you need the date to narrow it down.
Jim

Mine is also a yj block. 67 326 2 barrel. Jimbo

If you are suspecting that this may be the original block and if this car was originally sold in Canada you can call Pontiac Historical Services in Oshawa at 888-467-6853. They will have this information about your car and charge a fee for that information. The US PHS has the build sheet information as well if you need a more detailed description of the car.

Hey
where would i find the date on the block?? also does it say on the block right under the valley pan under the intake as i saw on another pontiac motor i have, a "00" for 400, and so on?? thanks
Nick

Date code will be next to the distributor, raised numbers cast into the flat. Block code is cast into the right rear of the block, just below the passenger side head. You need both for 100% ID.

Many blocks have the displacement cast into the side, in the area around the freeze plugs.