[Shop-talk] reinforcing roof joists

[Tim]

A qustion for engineers here maybe?

I want to hang a Datsun Roadster car body from the joists above my shop 
and garage space so I can start working on a frame in the shop.

The joists are approx 2' apart and made of 2x4s. The roof is a 4 12 
pitch. The car body might weigh as much as 700 pounds but I have yet to 
get an accurate answer. (I thought I had read at one point that the body 
weighed between 400 and 500 pounds.)

What do I need to do to reinforce the joists in order to be able to do 
this? Or is this just too much weight? I've seen pictures of this having 
been done but do not know whose they were or what they might have done 
to be able to hang this kind of weight.

Thanks!!

tim