xj400s diversion

[mjddla]

Hi all new on here and wanted to firstly say hi and secondly ask for advice on whether my latest idea will or will not work...
My daily ride is a 94 xj400s, and I have aquired a xj600s engine from someone that tried to top end rebuild it with inferior parts but it is the bottom end that is gone. So I'll get to the point, does anyone know or has tried to fit the 600 top end to the 400 bottom end? To me they look as if they would and measurement wise I think they will but before I get stripping thought id put it out there first

[bev]

I'm no expert on the 600 but if I'm wrong you'll be flooded by responders telling you so.

I believed the 400 was essentially a sleeved down 600 engine. so the top end if you mean pistons/barrels valvegear etc should fit.

Personally I'd rather fit a straight swap full 600 engine.