The answer to the first question is NO. The 525 is a 251 the 535 is a 265 cubic inch plus the last 535 models have an American engine while the other ones both for the 525 &amp; 535  were built in Canada and not all parts interchange. Remember you could have a 2,3 or 4 row head for a 7300. Also wide and narrow for the 3 and 4 row heads. Where are you located?