Originally Posted by SmileGuy49
Thank you so much for all the great info! I am going to stick with the 218 because it is the original motor in running condition with 4300 original miles on it. I am doing tons of custom interior work, so it is not that I am all about keeping the car factory original, but like you said, I am not going to see 100 flatheads at the next car show. I figure it is just a little more special that it is the true original engine. Thanks a ton for all the great sites for parts! I was going to create another post asking about trans but you took care of that one too! I am excited to get back into the garage and give my 218 a makeover!
If you are wanting to keep the original engine, you can still upgrade to a 230. All you would need to do is find a 230 crank and matching rods which will fit in your 218 block. You would also need to have the 230 flywheel or do some minor machining (about 3/16 inch) on your 218 flywheel or the mounting surface of the bellhousing where the starter bolts on.
The bore of the 218 and 230 are the same.