numbers matching engine, is it important?

[Pir0San]

So, I need to rebuild my engine. I have two complete P30 blocks, my original numbers matching block, and a donor block. The original P30 has a spun rod bearing, which ruined the crankshaft. The donor block is in my Z right now, but burns oil pretty badly. In the sake of making numbers match, would it be possible to swap the crank and rods from the donor block and put them into the original block, since the original crank is damaged? I figure that doing it this way would make it so that the value of the Z would theoretically be more due to numbers matching.

Also, the original P30 has been sitting in my garage for close to two years, and has a slight bit of surface rust on the cylinder walls. I tried to wipe it off with some WD-40 on a cloth and buffed it dry, but it didn't seem to make a difference. Here's a pic of how it looks:

By the way, sorry about the quality of the pic, I only have my cell phone camera.

[=Enigma=]

It will definitely be worth more to someone who cares with the matching numbers. I would be willing to bet that the rust in the cylinders will come clean with a mild honing or most defintely if you bore it out. If it were me,knowing what little else I know about the original block, I would use the original and rebuild it using the good crank and rods. Hopefully someone who has been through this will chime in.

[Pir0San]

thanks enigma, that's exactly what I was thinking myself. I figured that if I were going to rebuild my engine, I might as well do it to the original block. I was planning on getting the block hot tanked and have the cylinders honed, having the crank micropolished (and the rods too if they need them, someone will have to chime in as to if this is necessary when doing a rebuild), buying a cast iron ring set, and replacing the crank and rod bearings.