TurboVWguy

I got a 86 4runner recently to replace my 87 pickup that my little brother totalled a little while back (he had just gotten his drivers permit and i was teaching him how to drive, we were both ok.)anyways, The 4runner was running beautifully for about 6weeks then the timing tensioner broke, (thats why its important to use high quality engine parts and not crap from autozone and other places like that, cause the tensioner did not even look old.)So I replaced the chain, gears, and tensioner and put everything back together, The truck ran great for a day or so then i started to notice small puffs of white smoke and a small amount of coolant consumption, but no milkshaking, plugs looked pretty good too, a few tiny steam spots on the plugs but not many. Obvious symptoms of a bad headgasket. I dont know if i damaged it in some way while messing with the timing cover, or when the tensioner broke in some way it damaged the headgasket or head. I dont want to have to worry about my head now being warped or damaged I just want my truck to be back together right and reliable. So, I ordered a whole new head/cam and head gasket kit with new head bolts and even a whole new timing chain/gear kit so I have the metal guide I ordered it all from engnbldr.com.
However, I did drive the 4runner for 7 days just to work and home (lots of overtime that week and it paid for the parts so I had to do it.)maybe like 10-15miles each day. It really hardly puffed any smoke and I drained all the coolant out and just ran filtered water in there cause I figured it would be better to be getting that in the motor so it could just steam out more safely since it seemed to be only a very small amount leaking, It only consumed about 12 or so oz. of water. Up until about 3 days before i stopped driving it, at that point I topped off the radiator and I changed the oil to check on it and be sure it was not getting water in it, and it looked fine. But on the last day I drained the oil to begin the work and the oil was milkshaked. So I could have potentially been driving it for like 2 days (about 30 miles, maybe) with contaminated oil.

So I am wondering if You all here think that I could have already done damage to the rings or a main bearing?(or something else) Should I swap the bottom end from the other truck into the 4runner at this time? My truck had 210k miles and it was an auto, I got it from the original owner and he took good care of it So I am confident it has many more miles to go. My 4runner has 174,000 miles, and before all this happened it ran really good, did not burn oil and got really really good gas mileage, it even ran really good while the gasket was damaged, Idled pretty well and all and did not really get hot. So do you all think it will be okay to use the motor thats currently in the 4runner?
I want to know that the motor will be ok for at least the next year or two so I can do the other work I want to do to the runner before I have to come back to the motor, but I am planning at some point to use which ever bottom end thats not in the runner and have it totally rebuilt to put back in there when complete.
Sorry this was so long but I wanted to include as much info as possible so I could get some good advice. Thanks in advance