New on here but here goes. Had a bad heater element leak on my '55 Chevy 3100. I couldn't get it repaired and the only other option was a replacement core at £300 ($450) which I thought was expensive, So I had a go myself. I removed the old core and replaced it with a coil of 10mm (3/8") soft copper micro bore tubing. Well it works ok, Not perfect but it works and at £8 ($12) total cost is good enough for me. I would post pics on here but cant see how to do it. Sorry
I took the easy route Eddie,I fitted the self contained unit from a good old Mk2 Austin Mini,and managed to tuck it up tight under the dash so only the control panel is visible just under the bottom of the dash in the centre and used the choke cable to regulate the control valve.
It chucks out plenty of heat for the small cab,the demist hooks right up and gives the passenger a little more leg room too.
Parts are readily available (and cheap) here in Blighty too.
Which reminds me I need to order a heater matrix for mine (£40) before the full Scottish winter kicks in!
The downside of course is I have a perfectly good original deluxe heater (minus heater matrix) lying in my garage gathering dust....