307 or 327?

[PanattV8]

Hey guys, writing from Chile!
I just bought a 1968 Impala Sport Coupe, also have a 1984 Caprice Classic.
Can you help me with the engine information about the Impala? The numbers are:

Block Casting Number: 3914638
Engine ID Number/VIN Code: 18T263742 and T0425DW

Thanks!!!

 

[Craig Hanson]

It's a 307 cubic inch engine. In 1967, Chevy started making the 302's in the Z 28 Camaro, which were 327 blocks (4 inch bore) and used the 283 cranks (3 inch stroke) and made high horsepower with a short stroke, high revving engine, 330 HP.

So now they had all these extra 283 blocks and 327 cranks laying around. Put a 327 crank into a 283 block and you get a 307 with about 200 H.P. By early 1974, H.P. was down to only 110 H.P. and Chevy quit making them. Hope this helps you

 

[tar6569]

DW is 68 Impala 307 Low Compression with Powerglide transmission! Unusual code but it makes sense since you are in Chile! I'm sending you a PM. Would like to get some more info on the car for my Impala research!

impalas.org/drivetrain