Originally Posted by 05Musclestang
Lube the hose if you need to but do not force them on or you could break/crack the new heatercore not even knowing,
Try spraying some silicone spray onto a rolled up paper towel and wipe the inside of the hose.
Also, the heater cores on the market now are junk. The solder joint where the tube meets the end tank is lame, and has a tendency to prematurely fail. The lifetime part warranty is great but it hardly justifies the labor involved.
The solder joint needs to be built up better. If you can do this, do it. If not, take it to a radiator repair shop and tell them what you want. It shouldn't cost you much (bring beer, and show up at the end of the day) DO NOT use rosin core solder. That is a type of solder used for electrical repairs. Use only acid core solder for this type of cooling system repair.
Ensure you put a restictor plug on the coolant inlet tube to prevent errosion
Pics and tips courtesy of Pat Pearson, fellow SVO owner (of like, 10 SVOs!)
Below are before and after pics