okay so i got a 283 in my 63 c10 and it ran great until a few weeks ago when i was at work. ive had it for about a year and i can tell the engine is tired and im probably going to replace it this summer. anyway, i was letting a friend of mine mess with the engine outback while i was with him, just messing with the distributor a little bit and adjusting the fuel/air mixture and such. it sounded great. it sounded like it was running much smoother and everything seemed much better than before, with just that little bit of tweaking. so he leaves and then i drive it away a few hours later when i got off. now, again, in park the engine was running fine, i could rev it up and it was totally smooth. i get probably 100 feet down the road, get it up probably around 2000 or above rpms (just judging by the sound compared to my suburban, i dont have a tach in the truck) and the engine starts sounding really weird. it had almost no power, there was all kinds of missing going on, and so i was going down the road at about 15 mph trying to get it to get in its groove again but it just wouldnt. so eventually i just floored it and it finally kicked back into whatever the nice mode it was in earlier haha. so i get it home, it sits for a few days, and then i was going to drive it up to my dads becuase we were putting the new bed on up at his house. now once again, it sounded fine in park before i took it up to his place, and did fine driving down a pretty flat, straight road. so then i get to his street (his house is about a half mile from my place) and turn onto it and you have to go up a pretty steep incline for a few hundred feet. it pulls up the hill about a quarter of the way, and then same thing that happened a few days earlier happened-lost all power and torque, just wasnt pulling at all. it sounded really weird, all kinds of misses. the engine definitely didnt sound like a normal v8. basically what should have taken 30 seconds to get up took like 2 minutes of the truck just crawling up the street, barely able to move. so finally i get it to his house and park it and we leave it sit a few days before we're able to work on it. so we go there a couple days ago and decide to try to mess with the timing a bit. we get the timing light out, and the white timing mark on the (pardon me for not knowing the name of this part) was way off of what we thought it should be. so we rotate the distributor a bit to try to get it close to where it should be and it sounds like its running a lot smoother. so once again i take it out to test it, drive down the street and back up. now we had it in park and it sounds great. it revs up fine, no conking out, no crazy noises liek when its in drive. so i put it in drive, take it down the street, turn around and try to come back up. i probably got maybe 20 feet, and then it just starts doing all that crazy stuff again. it got so bad it would just end up dying and id have to start it back up and keep trying. i probably had to start it back up 7 or 8 times before i got all the way up the hill. i just dont understand why its fine in park, and then gets all whacked out and weird in drive. we were thinking about replacing the sparkplugs, wires, and distrubutor to start, so we can just start with something fresh. just wondering if anyone has any idea of whats going on. basically the main idea im trying to get across is that in park, when its not having to push anything, the motor does great, and then when you put it in drive, when its actually needing to move something, it just ends up dying, and it never did this before my friend messed with the carb and distributor. thanks for any help.