C5 to AOD on my 65, is it worth it?

My fastback came with a C4 green dot which I just recently changed to a 82 thunderbird C5. I am using my car more especially on the freeway. My mechanic has an 87 mustang AOD which he says will give me an extra gear to cruise better. I would like to know of the guys who have done such a swap feel it was worth it. I just spent $500 on the C5 upgrade; this AOD will cost about another $500 to $600. What do you think?
 
it is your dollars...

Well 500 - 600

Then you have all the other swap gear...

If you use windsor fox ... tack on another 300 - 500

It can be done for less....

but you can be assured you will have to add at least 200.00

so...

700 - 800

about 245 gallons of gas saved will break you even...

700/2.85=245

so...if you increase your mpg by 5mpg you will have to drive 15000 to roughly break even...assuming my math is correct...

so me I would not bother just for the efficiency...

I would and have looked at for " feel & streetability, and to be able to run 3.55's and still reduce rpm at highway and thus save a little fuel...

The choice is yours...

me $$ is tight so I found a built c5 and going that route...

If you do choose to...drop me a PM about your current c5 ;)