Heater core replacement - Clayton Classics

Replacing a rusted out heater core in my 54 xk120 OTS. Moss Motors distributes a unit from Clayton Classics. There are two major differences.
First the new core is 1/2 inch thicker. I am assuming that by removing the 1/2 inch spacers on the fan motor that the fan will then be lowered enough for the blade to be attached to the impeller? They do supply new clips to use because of the thickness. Second item is that the intake and exit tubes are 3/4 inch longer than the original. Seems like this will be an issue and perhaps they need to be cut to proper size.
Has anyone had experience with this retrofit? Thanks – Tom

Does anyone need a heater core replacement. I can relate my experience as I now have this installed.

I am about to order a Clayton core for my '53 DHC so any tips or suggestions from your experience would be very helpful. Thanks

I was able to modify the one that I got from Moss motors to fit properly (about 1/2" thicker than original) but it may be better to order the smaller unit as described by the following message from Clayton directly:

The design of the element is different from the original and is a higher performance unit which allows better air flow and heat transfer. If the LE15-7J is slightly too wide at 3” then maybe the LE15-5J at 2.25” was the direct replacement for your heater element?

Thank you! That’s helpful and I’ll consider the smaller sized core.