Heater core question

[rockyrivermark]

1970 c10
350 cu 350 auto
Non Ac truck

Finally got around to removing the heater box because is smelled like rat nest when I turn on the heater.
Cleaned out the heater box and want to change the heater core while I'm in there.
Local auto parts store had one in stock but the body was too wide to for the metal retainer brackets.
I read online that this is a problem.
Does anyone know of a manufacture that makes a replacement core the will accept the retaining brackets without modifying them?
Thanks
Mark

[macdaddy70]

I read several posts on this where the owners purchased a core and it was not the correct size. There are places that are cheaper, but I went with classic parts (68-231C). It is more expensive that the all aluminum version, but mine fit with no issues. Brackets fit perfectly and there was no interference with the box. And works almost too well. Hope this helps.

[GASoline71]

I got one from my local Napa and it fit perfect.

Gary

[halfstep]

Easy, inexpensive solution:
My method creates a stud that will come through the housing and be secured with a nut vs the original screw/bolt that threads into the bracket. Easy to install but the stud/nuts aren't as discreet as the original screws. Black painted cap nut looks just fine.
Home Depot - 3 ft. length of 8/32 threaded rod. $1.97
Cut to approximate length. Bend to replicate original bracket with a little extra. Form and adjust as necessary for modest protrusion through housing and secure with nut - trim length and finish as desired. Obviously when/where you cut the rod you'll file the cut end to allow the nut to thread on/off. You also might thread a nut on below your cut and after filing you simple run the nut up to clean/finish the rod end.
You may insulate the threaded rod where it sits against the core as it is essentially a metal file! You don't want it bulky so tape, heat shrink, etc.
My core came with a sticky back foam insulation strip to wrap tank sides and bottom against rattling against the housing. I'm not sure I like a soft foam for this but it's probably OK and there are lots of options for this.

[F.A.A.benny]

There were two sizes available from the factory but unfortunately the vast majority have the smaller one. And the aftermarket aluminum heater cores are now being made with the uncommon larger tanks. They used to be made with the more common sized tanks but who knows why they changed them. Every now and then a regular auto parts store will have the common sized brass copper heater core. But they have pretty much been phased out at auto parts stores. Some of the classic truck vendors have these brass copper heater cores but they are charging 3 times the amount of what the auto parts stores have charged. Who knows they may have bought up all remaining stock. Anyhow, the other option is to have your original recored at a radiator shop. With this option you get to keep your original Harrison tanks. I made a video of this issue and my solution which is to resize the brackets. I know that some would rather pay the extra $60-70 but I prefer to resize the brackets. https://youtu.be/XbRRvkQUCGk

[wpavlis]

I got a copper and brass one from NPD for about the same cost as an aluminum one. Worked great

[In The Ten Ring]

I took my original over to a local radiator shop and they found me a direct, brass replacement. It fit perfectly.

[Mike harris]

I used this one from summit SUM-382167
Fit very well and I was hugely impressed with the quality! Bit of a PITA to get the heater box off the firewall though

[rockyrivermark]

I found one online. For a decent price. Brass/copper.
I pulled the the housing already
Bit of a pain but not terribly bad.
Thanks for all the info!
Mark