Ok, been on a crash coarse here over the past few months.  About to start a small hay operation and it will be nearly all Oliver.  I've picked up a 65 and a 66 1850, I think it's a 66 1550 (haven't taken the time to look), two 620 balers, one with a 19 thrower and a 565 5 bottom (4+1).  Now I have my eye on a 770.  I've done a lot of homework on the 50 series, not so much on the older stuff.  Need it like another hole in the head but, it's now a disease.  I'm looking for something that's functional.  What I mean by that is, power steering and maybe 3pt.  Eyed up a few later super 88s that had the PS but just not ready for that yet.

What are the variations of the 100 series tractors?  I think (probably not) I have a grip on the basics, diesel, gas, clam shell fenders, grill, really focused on the 3pt.  Although I get it runs my rotary rake, Tedder, wagons and even balers just fine, it would be nice to be able to use it for whatever.  The one I'm looking at has the checker board grill and flat top fenders so I think that means after 1960.   It has 3pt kinda, think it's called power lift maybe???  Its a cylinder with the upper 3pt arms and down links to the draw bar.  Not really 3pt.  The upper link base is there but no link.  Where is the line at for newer style brakes, the PTO housing  (I think I saw a 58 or 9 with a different housing), 3pt, the major leaps leading to the 50 (1000) series???  Can this style set-up be converted to true 3pt?  I imagine the problem is, no pins on the casing for arms and prior to draft control.

This would be my only gas tractor, even though it's all dropped now (prices), it's something that wouldn't be drinking out of my fuel tank and the only thing not diesel. Have a couple JDs that take the beating, 4700 and a little 655 mower.  I'm doing this because taking the backhoe on and off everytime you need it for an implement sucks!!!  

Another question is, since the ethanol push, every carb I have is fowled, how susceptible is this to tree hugger gum???  And what lead additives work?  Haven't seen 104 real lead in years now.

Thanks for the help!