Will 14bolt 13" Brake drums off a 88 1ton Duelly, fit an 87 single tire 14bolt? Thanks in advance!

I dont think that will work for you, The DRW & SRW housing's are different. The backing plate mounting flange on a DRW is set farther in on the housing to be able to take the big offset of the drum. The brgs and seal are the same but the only way that might work is to move the backing plate flange to the correct position.

No they won't. SRW axles had a completely different setup.

Here is a SRW drum followed by a DRW drum. Notice the "hat" is much taller on the DRW. That is to compensate for the offset of the dually wheels and so that they are centered further out.