The faults if any between different lift pumps and injection pumps would not be identical even if they existed. Certainly both could be bad in some way but it is again almost certain the faults would be different.

Since Mr hunter has seen jelly like substances hit injectors before as long as you have fuel pressure indications in the injection pump at 1800 rpms. Having the injectors checked and cleaned out if the need is indicated makes sense. I am all too familair with straight waxing of the fuel at really low temperatures so the concept is not alien to me. The rule is never buy fuel from a pump that has a heater on it in cold weather especially. Unless you have one load of fuel thinners in the trunk.

Or grab a set of injectors out of one of the engines you pulled the injection pumps from if cheap and give them a try. Turn the engine over with the starter with the injectors out as this may also clear any residual junk that may also be present in the injector lines.

Since it is now a different injection pump I assume there is no impariment of it's delivery valves with junk as might be the case with the original injection pump.Although this is not much of a consideration if any because the engine is running almost the same except a little better in some ways now.So I would still flush those injector lines as well before installing either your current injectors once dealt with or a test set from a wreck if cheap enough.

There should be a relief valve present somewhere there. I have seen it mentioned that it was further along the system on one car. Right or wrong I do not know. There was one situation where the relief valve was on the input to the pump as well I think. A misteak of installation. Either way whatever was the situation previously it did not stop normal running in your cars case. Unless when you changed pumps there was some change relating to the relief valve. Again any form of real pressure present in the base of the injector pump at 1800 rpm deals with this issue. Or during the process to correct the low pressure if present will.

I have nothing but respect for Mr.Hunters abilities and experience. It is a wise decision to converse with him. I have not had the need to yet for one of my own issues but that day will probably come. His helping people out goes way beyond the norm. Also it is not all that simple in some cases to do so. Human nature being what it is people do things like leave important information out when describing their issues.