does anyone have hollander interchange book for 73 chevy 4x4

No it wont! I might get corrected on this and there are some exceptions. '73-'87(and 88-91 Suburban, Blazer, and Jimmy) boxes from Chevy or GMC 4x4's will interchange.

You can use the 2x4 box on a 4x4 *if* you're doing crossover steering. Reason being that the 2wd box steers 'side to side' and the 4x4 steers 'front to back'.....

I don't know of any differences between the 73-87's except for hose flange differences. My '79 takes different hoses than my '85 did - but only the ends were different. Check it out - you may be able to find hoses that'll work. Maybe not easy tho.

Jeremy