I bought this old truck for 500 bucks from an old buddy.  After I fixed almost the entire braking system all except the air assist and the lines.  I had run into hard times but eventually got the truck up and running.  I remember riding around with my friend when the truck was his and it drove just fine as long as he kept a few quarts of dexron/mercon3 on board.  Well not long after I finally was able to drive it the transmission started slipping real bad had plenty of tranny fluid not too little or toomuch.  So then I started asking almost everybody  I came in contact with if they knew where I could get a 727 automatic tranny.  A few months later I had acquired 4-5 727 transmissions.  Then I pulled my transmission out and I noticed that mine was much shorter then the others.  I did a little research and found out that you cant just swap out the shafts nope Another thing I learned was that short shaft 727's are sometimes hard to find yet the long shaft 727's were being given to me.  Then my neighbor and I decided to do away with the short driveline and make a married unit.  longshaft 727 connected to a splined yoke that was bolted to the transfer case.  Now I dont know if the trannys were good or bad.  but I have gone through 3 of them rather quick.  They all did the same thing started slipping real bad.  I would also feel the shudder as if something was out of balance.  So I have decided to just take the original to the tranny shop and pay them to rebuild it which really sucks wasting all this time on installing and uninstalling those transmissions especilly when doing so with blocks and jacks and block and tackle in liew of a actual transmission jack and striking a deal with friends that say they will help but never do.  the 318 that is in the truck runs but barely I get backfires hard starts when its warm misfires.  I know that the number one plug wire on the distributor cap is towards the front of the truck positioned at 5 o'clock inline pretty much with spark plug number 1.  and if I try to time it with a timing light it will not run at all.  and if i try to time by ear I can get it close but it still misfires and plug wire number 1 is way far advanced (I think) and sits somewhere between 7 and 8.  I'm thinking the timing chain skipped or jumped.  So I'm trying to decide if I should fix the old motor that is in the truck or buy a 413 wedge that has 30,000 original miles for 250.00  And would the 727 and 413 make a good team?  Any comments hints or opinions would be appreciated thanks