is it a longer rod will the crank also fit
To put it simple the 25 block Is shorter than the 28 block, and the rod from either engine will interchange. You can take the older 28" I/C ohv rod (small journal crank) and put in a 25". The only real difference other than they look alot different is that the ohv rod cap is a little stronger. And on that note. If the rods look different the bolts and caps will not interchange, heck the torque specs are even different. Now as far as the crank goes, if you are trying to put a 28" crank in a 25" block I think you will have clearance issues, not to mention about 70 thou of piston sticking out of the block that would either rip the head off or break something internal.