Getting the body back on over the chassis rails

[Discopotatoes]

As per the title, I'm doing a body off restore and have been trial fitting the repaired chassis, the problem is each time I put the body on it catches the upper chassis rails, is the a knack to it or is it just fing tight?
I really don't want to damage the powdercoat or the inner wing paint so any advise muchly appreciated.

[magpies]

generally the rear has to be much higher (approx 600mm) than the front and also slightly (maybe 100mm behind the chassis. Then as it is lowered when near the chassis move it forward (still with the rear high) and then gently bring the rear down and forward to it's correct position.

[Discopotatoes]

magpies said:

generally the rear has to be much higher (approx 600mm) than the front and also slightly (maybe 100mm behind the chassis. Then as it is lowered when near the chassis move it forward (still with the rear high) and then gently bring the rear down and forward to it's correct position.

that will explain it, i was trying to do it level.
thanks