Hey all, I am a proud owner of a '71 C/10 and as I'm sure all of you know, they never are really "finished". I've built and installed a small-block 406 with a Saginaw 4-speed with the 3-ring (3.50 first gear) input shaft. I'm pretty sure I'm gonna have to replace the pressure plate and clutch and main bearings due to a vibration I have and it seems to be affecting the oil pressure by putting excess wear on the bearings. Domino effect I guess. I 've changed over to AMSOIL 20W-50 oil. When the engine is cold to warm, the oil pressure is fine, but when everything is hot, if it idles at 20 lbs. I'm lucky, sometimes less if it's a hot day out. The pressure was better when the engine was new, but it has less than 10k mi. on it now. The wide-ratio trans. works great with the 12-bolt 3.07 rear. My dilemma is, I don't know if I should go with a Posi, Limited-slip, or one of those Powertrax lockers. They all seem to be a good idea, but which would be the best? The truck is, well was now, kinda a daily driver, with a little "playing" from time to time. Nothing major, just "blow the soot out" every now and then, you know. The truck is nowhere near perfect, but after all, this is my first build, and I want to try to do it right. Any help at all will be greatly appreciated.