I am putting a door from a GTA on my '86 Z28. The GFX holes for the middle three are different than a Z so i will need to fill those and redrill. I would like to hear which methods/products have given good results filling these holes. Thanks....

 

BONDOIt works great or you can use fiber glass filler.Since the door filler gfx will be covering this patch job it shouldnt be too critical.

 

Wasn't it a GM defect that they didn't put holes in the bottom of the doors? water and dirt would collect in the door causing it to rust through.

And on certian years of chevy trucks the quarter panels have a lip that collects water leading to the same rusting out problem. My bro's truck was way past warranty and GM still paid for half of replacing and painting both rear quarters.

I know some people who have accually drilled new holes and rust primered them. I've done it to my grand am. But the inside of the door was already severely rusted (outside was perfect) so I probably just gave the rust a easy way to come out. I'll find out this winter.

I say spray (brush may work better) some rust primer over it and call it a mod

 

Weld them in. It isn't overly expensive, and is the only thing that will really last. Bondo will eventually crack out.

 

Metal into metal is the proper way. Either weld or lead the holes. If you choose this way I would let a pro do it as not to warp your door from excess heat.

If you're a do-it-yourselfer you could bondo them in. It would be not as critical if the area isn't visible. If you have access to the inside of the door I would lay a fiberglass patch over the hole on the inside and bondo the outside, to give it something to butt up to.