Fenders on my Challenger have a big gap where the hood and the doors meet, they are out of alignment about 3/4 of an inch, I heard fender/door/hood alignment on a E body is tricky , whats your thought? farm it out or can a Shade Tree Mechanic do a good job?

Depends on the paint quality and your skill level. It's not terribly difficult to align panels. Start with the doors to the quarters and rocker panels, then work your way forward. Keep in mind you can compensate for worn hinges, but it's best if they are in good shape. Unless something has been bent from an accident, it should be pretty straight forward to line everything up.

It isn't that bad to do it yourself.
Be prepared to spend the time to get it right.
Pay attention to what adjustments you make and in which order.
Some adjustments will modify the previous adjustment.
Get the small rubber 3M paddle for body putty. (about 2"x3"x3/16")
I use one as a go-no-go gauge when aligning panels.
It seems to work really well.
Plan to spend some serious time on making it dead on.

Good idea is to run a couple of layers of painters tape along the panels edges to keep from chipping the paint and setting the gap.

It can be done at home with some careful work and a helper.

Plan to spend $90 an hour for a pro to do it.

Taking a swag, I'd say 8-12 hours worth of work.

Thanks fellas, going to go for it, the paint is trashed so the plan is to remove ,sand and prime while off the car then re install and hope I can get a really nice fit, can't be any worse than what I have cause for some strange reason the previous owner left one fender to body mounting tab on each fender with out a bolt thru it, its also got a 1/4 inch gap between the body and the tab

btw I tried getting a local auto body shop but those guys just are not interested in this type of work