I have used that liquid tape stuff where I had to tap into the wiring harness on my 5.9L Cummins when I installed the SuperChips Digital Propane Injection system. There was just no room to get in there to tape the connection after soldering the wire tap.

Those molded "T" heat shrink look interesting, Might have to see how expensive they are, but likely overkill for what we are doing on the car.

The Double wall heat shrink is the heat shrink with the glue inside. I didn't know it was refered to as Marine grade, but I do know Marine grade wire is flame retardant and the copper wire is tinned to resist corrosion.

I have other lower priced crimpers too, but the MSD one does the best job. The MSD crimpers are the most expensive ones I have. I know there are others out there that are much more expensive, but I'm not wiring an airplane or rocket either.