440 cooling system capacity gallons?

Is the rad or the heater core leaking? May I suggest soldering the leak instead of the bars' leak material. It may or may not work & may or may not clog some cores. I have no actual experience with it though

Forgot to mention there is no heater. I think its the head gasket thats leaking.. every so often some drips down to the header then steam. before i tear it apart i want to try this particular tablet stuff. i think its safe to try lots of people have good luck with it.

I'd suggest borrowing a radiator pump & pumping the system up to 15 lbs & see where it's coming from & I'm assuming your running header bolts which are notorious leakers & you could sub in an OE double ended stud & if needed trim some of the fine threads on the outer end off so the flange will fit back over it easier. Only need enough threads for the nut to fit flush when you're done & can get a high(e) grade nut that is thinner to shorten the length needed even further for easier fitment yet & can trim the "points" on the hex nut to help on apps where the tube makes a sharp turn

BTW, thanks Cab I'll estimate around 3.5 gallons then..

Robert, I forgot to mention it has Eddys on it, but I'm trying the tablets first and will go from there.

Use this stuff instead, it is used differently than barrs leaks and is way better. It's permanent and will last forever. K&W Block Seal

Well the tablets didn't work. Rather than monkey with additives I'm just going to put a new head gasket in. I'm getting pretty quick at header/manifold and head R&R. I'm just glad it's the passenger side.

Im fairly sure it's seeping out behind one of the header tubes, down onto a boss on the block, then right onto the header collector. If I get the header out and it's not that, i'll go from there.

The Eddy Heads should have blind, dry, exhaust holes, I have seen a lot of stock Mopar heads leaked coolant out of the exhaust bolt holes

Yeah it wasn't leaking from a header bolt, but the header tubes were obstructing my view. I pulled the header and saw definite seepage back there, where it would run down and drip onto the collector. New Felpro 8519 head gasket installed after careful cleaning of the deck and head. Tomorrow I'll fire it up hope for the best.

Just to close this thing out. After the new head gasket, and it still leaking, suddenly there was a 20/20 hindsight like clarity and the smell seemed obvious.. it was oil, not coolant.

I pulled the intake off and found a dent along the back end of the valley pan gasket, where in the past I'd noticed and remembered to put extra RTV and I purposefully positioned that dent up front. The leak started after putting it all back together after having the heads off to replace bent valves, I had forgot about that valley pan dent thing and stuck it on without any extra RTV in that area. By chance it ended up in the back corner that time.

So it seems it was leaking oil from that area, and/or the corner, down the side of the head/gasket area, and onto the thick boss then onto the header.

So I took it all off, cleaned the intake gasket, cleaned the head, started with a fresh coat of black RTV, extra by the dent (which I put up front this time) and extra on the corners. Let it cure all day Sunday, fired it tonight and NO LEAK, no smoking header, hooray.

I'm glad you found it, I think I would have straighten the dent out or fill it in, if it is a seperate valley cover, and then siliconed it as extra insurance It looks like Mr Murphy likes messin with you also BTW, I hate gremlins like that Oh ,WELL learn and move on, I'll bet that won't happen again