Aftermarket heater core replacement

Im going to be replacing my stock heater with one I got from Summit Racing thats originally designed for hot rods and those sorts of things.

It has two lines, one in and one out which I will be hooking up to the stock lines that go through the firewall. However, I will be needing to cut the lines which are copper and was wondering if I should put a lip on them or not.

These are the stock copper lines that go through the firewall, which I will cut right after they go through.


This is the lines into the aftermarket heater, that does have a lip


I will be using heater hose to connect the two.


So, for the stock lines that go through the firewall, do I need to somehow put a lip on the line, or will one or two hose clamps do the job? Or should I look into some sort of plumbing glue that is rated for high temps? I would rather not have this fail and shoot 210* coolant over my passengers legs!

1-2 hose clamps will do the job if you snug them down fully... but I would put a lip on the line for peace of mind, I had a double-clamped fuel line let loose due to low quality hose clamps last fall. I generally throw the tubing in my flaring tool and put a really halfhearted single flare on the end (flare fully and the edges of the tube will cut into the inside of the hose!) but ideally you would use a bubble flare tool.

There's 40psi on your fuel line. Your rad cap releases at 16psi. Totally different ballgame. Still, it's a good idea.

Now I just need to figure out how to put a lip onto a 3/8'' pipe....

My flaring tool goes up to 1/2" iirc. Plumbing aisle of home depot, cost under 20 bucks.