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i need a new heater core plug for my intake manifold (edelbrock) because i cant get the old one out of my old intake. i also need a vacuum plug for the transmission vacuum line, the old one was to small. anyone know where to find these? or what sizes they are, the heater core one is the one in the back passenger side and the vacuum is on one of the runners behind the carb. also i need a new oil pressure fitting/sender thing, machine shop messed mine up taking it out, i dont even know what the proper terms are fo these so im having a hard time googling them. thanks
FYI, the heater hose fitting needs a restriction (1/4" hole) to reduce the fluid flow, otherwise the heater core will balloon and burst. AC cars have a vacuum controlled valve that has a restriction, and OEM hose nipples for non-AC cars have a restriction as well.
Warning! Do not use steel plugs or fittings in an aluminum intake! Previous owner did this, and I ended up cracking the intake trying to get the plug out.
Use antiseize on any plug or use aluminum or brass plugs. Yes the steel can seize. I am going remove the steel plumbing adapter for the heater hose, since this motor will see over 5000 rpm and going with the reduced factory adapter, it could be fun.
FYI, the heater hose fitting needs a restriction (1/4" hole) to reduce the fluid flow, otherwise the heater core will balloon and burst. AC cars have a vacuum controlled valve that has a restriction, and OEM hose nipples for non-AC cars have a restriction as well.
Can you please post a photo of the vacuum controlled valve? When I replaced my factory 2bbl intake in my AC car with an Edelbrock 4bbl I installed a new brass fitting at the back of the engine. I have not had an issue yet, but I also don't run it at high RPMs. My old manifold seemed to have just a straight pipe as well without a vacuum controlled valve (see photos below), although the service manual seems to show that it should have one.
i need a new heater core plug for my intake manifold... i cant get the old one out of my old intake.
I had problems with getting steel fittings out of both a cast iron and a very rare aluminum intake.
At the time, I worked at a manufacturing plant and one of the maintenance staff heated the manifolds with an acetylene torch, cooled the fittings with oil, and popped them out.
He used the appearance of the aluminum as a gauge to avoid getting too close to melting temperature. I admit I was worried on that one.
Perhaps you can find someone at a repair shop who has similar skill.
Can you please post a photo of the vacuum controlled valve? When I replaced my factory 2bbl intake in my AC car with an Edelbrock 4bbl I installed a new brass fitting at the back of the engine. I have not had an issue yet, but I also don't run it at high RPMs. My old manifold seemed to have just a straight pipe as well without a vacuum controlled valve (see photos below), although the service manual seems to show that it should have one.
Coincedently, I have mine here at work. Going to be borrowing shops tools to clean up and re-tap the port that got destroyed when I removed the steel plug from my intake.
IIRC mine was 3/4 NPT but you may need a combination of different size adapters to get it to the size that fits.
are you trying to plug the port or find use a similar fitting on the edlebrock?
I just plugged my edlebrock port as i bypassed the heater core.
I'm looking to get something similar to what is the picture, I might just get a plug for now so I can break in the motor and then I'll also know what size it is
It is 3/4npt... I just re-tapped min out after damaging it getting the steel plug out...
Did I mention not to use steel plugs or fittings? LOL
BTW... From what I understand, this specific part is for A/C cars. If you don't have A/C you don't need the switched valve.
There is a restrictor in the fitting, though that you still need, so you can't just find a fitting at Lowes and use it. You'll flow too much thru your heater core if you do that.
Last edited by David Sloop; Sep 30, 2021 at 04:49 AM.
