I was wondering if I need to drain the coolant on my 340 before fixing this leaking bolt? The leak is coming from the front left intake bolt and running down the front of the block. What sealer would you use? Thanks any help appreciated.

none of the bolts are in water

on the end its a blind hole the others are in the oil,and oil can wick up the threds and pool in the intake by the bolts

sounds like it may be an intake gasket not sealing at the water port

did you use any sealer on those water ports?

the back is blocked by the intake but still you should use some sealer on the back water ports also

check the water pump bolts that go thru the t-chain cover as well

make sure your not getting any water in the oil pan while your checking

best bet might be to pull the intake and redo the gaskets with sealer on the water ports

have not talked to you in a while,hows it been going?

The front/rear gasket(s) are a bit too thick holding the intake up just a hair too much letting the water port(s) seep and it's bleding over to the bolt/hole. Drain the coolant/pull the intake and lay down a wide carefully place swath of clear silicone instead of the supplied gaskets, Clean the surfaces 1st w brake kleen.

Hey Scratch thanks for the reply. I just looked closer and its not coolant, I guess its oil it seems to b rust colored, slow seep and I noticed other front intake bolt has a little on it. Intake was sealed before install, J heads milled down some and LD340 intake milled to match.

check to make sure the bolt is not bottomed in the hole

if it is then grind a little of the bolt

i would do that on all 4 corners

milling the head and intake could very well make the 4 bolts to long going in the blind holes

when you milled the deck side of the head did you mill any off the intake surface of the head?

and then mill some off the intake also?