do not use coolant sealant
might block also other parts in the system, including engine coolant bores.
and use the search there with 'heater core'
Patrick C750 has also posted pics how to block the heater core for a while till he found time to repair the heater core.Shogun E32 Tech Tips: http://twrite.org/shogunnew/topmenu.html
Re: do not use coolant sealant
I replaced heater core four months ago
Just timely for the winter. Before that I isolated the leaky core from the main engine during the summer. The number of pairs of electrical plugs to disconnect is below ten, so label them properly and you'll be all right. Also, I did not remove the dash. Nor did I remove the tube frame on the driver side. The tube frame on the passenger side extends across the heater core so when you remove that frame you can remove the ten or so tiny metal clips around the black plastic door (12 inch x 10 inch). Remove the black door and you can see the three pipe endings and the heater core itself. Search for instructions with photos on Shogun's site.Patrick C 88 750 159K