Hi,

I just pulled my 390 engine to try and track down a coolant leak coming from the rear of the block. I was hoping it was a frost plug, but once I got it all apart it appeared to be leaking through the block wall somehow...after cleaning it up a bit it seems like there is a small round plug of some sort (approx 1/4") on the drivers side about half way up the engine...does anyone know what this is? or how this leak can be stopped?

Here are some pictures I took of the location of the leak...it's circled in yellow





Thank you!!

 

That's kinda bizarre... are you sure it's not cracked right there?

 

While not very common it is a known issue with some FE blocks, read Dave Shoe's posts in the following threads...

332-428 Ford FE Engine Forum