I am stuck trying to install my heater core box with heater core on my 67 Firebird. I can't even take just the core and get the tubes through the firewall. I have researched here and read that you need to remove the fender. I just recently installed freshly painted fenders and don't want to remove the fender unless absolutely needed. I have slightly enlarged the holes on the firewall but did not help. So what is the verdict - yes I need to remove the fender or ? Thanks - six months on this headache.

Wouter had a nice thread on this a couple of years back. Try searching his posts. I do not think you need to take the fender off, but its pretty tight.

Thanks. I did come across that thread earlier. I almost think as is mentioned in various threads that the tubes are at the wrong angle. I have bought two from different sources (could be same manufacture)but unfortunately I have been working on this car so long and have had to move it twice that I don't have the original core to compare. I am thinking about trying to locate some solid flexible tubing (like used to connect hot water tanks) and have it soldered on.

I ran into the same problem. After much cursing and weighing my options, I did the following. I cut one of the tubes. Then I bought a copper coupler from Grainger and JB Welded the coupler to the portion of the tube that was still on the heater core. Then I installed the heater case / core to the firewall. Finally, from the engine side I JB Welded the previously cut tube to the coupler being careful to try and maintain the original angle. Hopefully, the pics will help explain. Oh, I also added some JB Weld to the solder area where the tubes connect to the core. This was the weak link in my original core. [url=[URL=http://s1273.photobucket.com/user/mgoblue83/media/06Nov2013120_zps942b8367.jpg.html][/url]][/url] [url=[URL=http://s1273.photobucket.com/user/mgoblue83/media/06Nov2013117_zps8b7e6b1b.jpg.html][/url]][/url]

Looks like a winner to me, thanks.

It's easier to just melt the solder with a propane torch and reposition the tube.

Be sure to use low heat and apply the heat to the fitting and not the joint so solder in the core and tank seam is not melted or leaks may develop.

No question that it's relatively easy to melt the solder and reposition the tube. I looked into that. The problem is that these heater core tubes exit the firewall behind the engine block with little clearance in that area. The tubes have fairly precise bends in them so that the hoses route properly and don't rub against anything. Yeah, you can resolder and reposition the tube, but in my opinion that's trading one problem for another.

It has to be better than epoxy on something that expands and contracts as much as copper does. I've repositioned 6 or 8 and non have leaked. It's definitely not something you want to do more than once, so pick your poison I guess.

It has to be better than epoxy on something that expands and contracts as much as copper does. I've repositioned 6 or 8 and non have leaked. It's definitely not something you want to do more than once, so pick your poison I guess.
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My point had to do with maintaining proper hose routing in the tight clearance area behind the engine block, not if resoldering increases the chance of a leak. I agree there is a concern with thermal expansion/contraction when using a coupler and epoxy. I have attempted to minimize this by using a copper coupler (same material as the tube). If you've been able to resolder the tube(s) and maintain good hose routing behind the engine block, then that would be the best. My estimate of how much repositioning would be required to be able to feed the "bended" tube thru the firewall suggested a problem with the hose routing. If in your experience the hose routing is not an issue, then resoldering to reposition the tube is a better solution.

Hey guys I did mine last year and had the same freakin results. I ended up ordering three different cores, Orielly's, Rock Auto, Summit. I took the Orielly's core and took it to my radiator guy and had him reposition one tube. I also had him build up the solder around both tubes. I also changed my old blower motor and found out the hard way that you do have to remove the passenger's side fender. What a pain in the behind!! with lots and lots of cursing. Get someone to help you especially if you like your paint. Also when your putting back your heater vents. WARNING!!! MAKE DARN SURE THAT YOU GET THE DEFROSTER Y SHAPED TUBE IN FIRST BEFORE INSTALLING YOUR HEARTER CORE COVER BOX!!! I also got the dum dum tape/putty for the engine side heater box cover from Ground up http://www.ss396.com/mm5/merchant.mvc?Sc..._Code=JCS-10459 This stuff really works excellent you cant screw up. Also if your changing your firewall padding your going to want to install the padding before you install everything else. Oh yeah the heater core box seal kit most of the foam pieces do have a place to go. My seal kit never came with instructions and the company that i purchased it from only could tell me that its for numerous years. This is what I experienced and maybe for others it wasn't so bad. I got my but kicked. I truly thought it would be a walk in the park and never did research before tearing it all apart. Good Luck!!