Heater box ideas / thoughts requested

My engine rebuild decision process has led to other components like tranny ratios, exhaust improvements etc. Research shows that with a 1 and 5/8" merged header system I'll obviously need new heater boxes and CIP1 sells p/n ACC-C10-6019 at $315. for the pair but these are the "lightweight version" and have no aluminum heat sinks in them which VW obviously thought was a good idea in the first place. Anyone with any experience with these...? Jim..le Guamaniac...do your heater boxes have the heat sinks in yours...where'd you get them please ? Thanks...

I have 1-1/2" units in mine; they look totally stock from the outside so I'm not sure if they have the aluminum heat sinks. Get them years ago from an advertiser in The Samba (can't recall exactly who).

If you've ever seen the inside of an original German heater box you'd understand why no one makes a larger heater box with an aluminum inner heat sink. I guess it could be done, but the cost would be prohibitive. I had a 1 5/8" set of heater boxes custom made 6 or 7 years ago. They are hollow, but do a decent job of heating the cabin.

Hey David! I don't know for sure about the heat sinks, but since they are stock VW I'm guessing they do.

I've seen people take apart an OEM unit for the aluminum heat sinks; ream them for the larger diameter pipes and put them in the aftermarket heater boxes.

We used to do that in the 1960's-1970's.

IT WAS A MAJOR PAIN IN THE ASS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

It sounds easy, doesn't it? - Just remove the cast-on heat sink from the stock, 1-1/8" J-tubes (a major PITA in itself), then run a 1-5/8" or 1-3/4" drill through the heat sink to bore it out and run a (supposedly) straight, bigger J-tube through the drilled-out sink and THEN get the damn thing to NOT rattle because it's no longer cast around the bigger pipe. Oh........and the heat sinks had a habit of moving in three dimensions when the engine was running/vibrating so they never stayed put.

If the stock heater boxes were $300 each, then the additional labor to make them bigger was sucking up another $150+ EACH!! And the end result was an inferior product to the stock ones (they leaked and rattled). Sure they put out heat, but an Espar gas heater was a whole lot more cost effective.