Help identifying engine. 3970010

[jay]

I've been told its a 305, but when I look this # up it give me multiple sizes like 302,327, and 350. A mechanic told me you can tell its a 305 because the timing of it. The tab behind the water pumo is at 12:00 instead of 1:30/2:00. I'm justconfused with the block number.

[foxyshazam77k30]

its a 4.0" bore block from about 68 to the late 70's. its either a 350 or 327. to find out for sure you'll need the block suffix code. that code is up on front on the pass side of the block. hope that helps!

[Fairlane514]

305's do have the timing mark at the 12 O'clock position as opposed to a 350 which is at the 2 O'clock position.

[Captkaos]

The timing mark is on the Timing chain cover, means nothing if it was pieced together...

[thefarmboy21]

The 3970010 block is probably the most common "350" block there is. As stated it can be any 4.00" bore motor of the 3 possible. More than likely its a 350 that someone has changed the timing cover on, or maybe a car engine. If it has a 6" harmonic balancer it's a 2-bolt (car) engine. If it has an 8" balancer it's a 4-bolt (truck or possibly a muscle car) UNLESS someone has changed the timing cover and balancer.....regardless it's still a 4.00" bore block and absolutely not a 305. A 305 and a 350 have the same rotating assemblies except for the actual pistons. Crank, rods, balancer, flywheel, etc are all interchangeable despite what some people may tell you. I've torn apart and built many...and I've read even more articles on the two.