That engines from the pictures has zero modifications done to it. I can see that the conrod is not the same and it COULD have been machined to eliminate like .01% of its weight which will amount to less than .00001 sec faster laptimes. In my own honest opinion if you were charged for a modified engine, you have been ripped off. Either the person that modified it only did port timing changes which would also have been noticed in the picture, or he just ripped you off.