hope im not annoying anyone but..

ive asked before on here and i dont have a 100% sure answer. so, can anyone give me the length of a rearend that i would need to fit a 70 dart? what is the measure? can i have pictures of where to measure from as a referance, because i dont exactly know what the "perches" or "flanges" are and where on them i would go off of.

so if anyone can take a puic of what to measure w/ a arow or something pointin exactly where to measure from, i would greatly appreciate it.

thanks!