A little background...it's a 76 pig with an 84 2F installed. I have run through ~ one tank of fuel (and 4 fuel filters...starting to clear up..seperate issue) and it has a weber 38 with FP regulator and pressure gauge. The original (1976) set up had no fuel return line associated with the fuel pump. The motor/fuel pump thats in their has the original (came with the 1984 engine) fuel pump with a return line set up. During the initial runnings with the first tank of fuel it would idle and the FP gauge would bounce like crazy from 0-5 psi (coming into the FP reg). It would also fuel starve at any rate of acceleration. Soooo, as an intermediate fix, out came the needle nose vise grips and I clamped the fuel return line (not 100% but enough to stabilize the FP gauge to 4-5 psi). Ran like a champ ..no starvation. That was thru December..and I topped off the tank (and bought a few more filters). I decided that the needle nose vise grips needed to go back in the box, so I blocked the fuel return line in a more permanent fashion. I fired it up a few times in this configuration (replaced a thermostat to get some heat going) and during these times I noticed black schmootz splattering out of my tail pipe...at the time I chalked it off to water/condensation...and it also had some annoying blue smoke. Hmmm, never did that before. So today was decent weather and I decided to see whats what. Fired it up...idle was OK, but stumbled on blipping the throttle. Blue smoke was prevalent. Tried to go for a little spin to see if she'd clear herself out. No luck there fuel starved and stumbling and blue smoke. Panic set in...compression is good 145-150 all across. Plugs black and sooty. Pulled the dip stick and oil was thin, overfull and smelled of Sunoco....viola... Fuel pump gone bad dumping gas into the crankcase. Sorry for the length..but now the question. Do I install an old (1976) style fuel pump w/o the return from the FP...or do I install a new style (1984) FP. If I go old style do I need the spacer ? If I go new style, do I block off the fuel return...or is this what made the 84 FP s*** the bed in short order ?