I was just going to start the process of putting the body back on the frame on my 69 when I noticed a little puddle under the engine... Turned out that one of the freeze plugs was leaking. Ok, would have been easier to deal with this when I had the engine off the frame, but still better to find it now than after the body was on. The material in the leaking plug was thin as foil, and I could poke a screwdriver right trough it. Judging from the stuff pouring out the coolant must have been sitting in the bottom of the engine for 40 years, it looked more or less like mud.
So, so I ripped out the old plugs, wich was not that hard, and now on to my question:
Any of you have experience with these kinds:



The idea seamed good with an expanding and easy to install freeze plug, but for me it just did not work, it was like they wouldnt expand. I installed them and turned the nut, but after a few turns the entire plug came loose and started to turn. I then took a new one and measured it (1 5/8) and then started to turn the nut (plug not installed in engine) while measuring, and I could turn the damn nut until someting snapped and the plug still wouldnt expand.
Is there something to this that I have not understood?? I should say that the parts were marked "China"... They are made by Dorman.

 

Just go to a machine shop tell them you want brass freeze plugs for a sbc or bbc which ever and install them, the old knock design is the best, i would flush the block out while there all out also

 

I have used them many, many times over the years for in car repairs with never a problem. They only expand a few thousands. In fact I ran across a couple the other day that are at least 20 years old.
Given the condition of your engine, take the time to pull it, flush the block properly and install brass ones. You don't want all that crud plugging up the tiny tubes of a possible alum rad, if and when.
BTW, there are 2 hidden by the bell housing.
The brass ones are available at any parts store.

 

Dorman has been selling that plug for decades...nothing wrong with them when used with a well prepared subject....the ones to stay away from is the rubber plugs....actually the 'brass plug is your best bet...they are also sold as engine kits for most engines including all Chevys....Dorman and Pioneer sold in most real parts stores are excellent choices

 

A few thousands? That explains why I couldn't measure any difference, my parts catalogue said they would expand up to 1/8in...

The block has been flushed and I ordered the brass ones.

What's wrong with the rubber ones?