Posted by Tim L. on May 22, 2000 at 15:33:43:
In Reply to: difference between b1 and wm300 posted by josh on May 21, 2000 at 22:29:49:
I believe the Wm-300 Series started in '61 due to the increase in cubic inches to 251. Also, I believe the 251 a is longer block. I know that the head bolt spacing is also different. As for interchangability the best thing would be to check the parts manuals for both the WDX/B series and the WM Series. Looks can be deceiving!