2003 Mazda 3..2.3 litre engine swap trouble
 

My daughter's car was knocking ( big end con rod), decided to swap with a know good engine ( video proof was provided, reputable shop)

Car in Missouri, brought engine down from Canada, my sons in laws figured they could do swap. Didn't go good, broke and bent valves.

I am now in Missouri and have pulled the head. Daughters original head is in pretty good shape, engine was very hard to turn over, noticed flywheel difference, 1/4 between block edge to ring gear on non original. Original had 1/2 inch clearance.

Do I need to swap flywheels?, I suspect so.

Heads look identical.

Anything else I need to watch out for?

Thanks for reading and hopefully someone might be able to help me and my daughter out