Coolant Issue

[norcalsvt]

Was picking up some of the cardboard under the stang & noticed coolant on the ground around .50 size. Traced to freeze plug at the rear of the block drivers side. looks like I can get to it. I saw a little bit of coolant on the edge & nothing above it, so I assume thats the leak. Couple of questions. How easy of a job is this to remove & replace. The block was painted blue after the rebuild, so hopefully the paint hasn't formed too tight a seal. I seem to be one of the guys that even though it can be an easy job, if something can go wrong, it generally happens to me. Also, can I still drive it until I can get to it on the weekend? This is my daily driver.
Does anyone think this would cause my initial temp spike when I get on the freeway?I am beginning to wonder if the temp spikes started when I noticed a drop of coolant on the garage around 2-3 weeks ago? After the spike the temp drops to normal.Never any overflow from the radiator.
Lastly, by draining the coolant from the radiator, is there still going to be a big gush of coolant comming out when I finally remove the freeze plug? If there is I guess I'l try not to be directly under it when I try to pull it out.

 

[iskwezm]

Its only gonna leak under pressure,so as you drive and it builds,its gonna leak.If you have access to it,just knock it out,and for ease of replacemet,use a rubber expanding type,or if you have room,replace with a brass and some sealer around it.Youll need to lower the coolant level to below the freeze plug level.Should be ok to drive short distances,just watch it.

 

[1966conv]

The spike and resulting lowering/leveling out could be the result of the thermostat opening. Your thermostat could be sticking just a little. Depending on the condition of the gauge, sender, and thermostat this could al be normal. These old gauges are an estimate at best. Get a mechanical test gauge and get your real numbers.