Most of the filler I need to use is on the rear quarter panels. They had a load of bondo I had to dig out to clear some rust spots. I'm worried that If I use standard bondo brand filler that the rear quarters will distort and get wavy after a bumpy drive.
another side track... The driveshaft on the car now probably won't fit the 6cyl tranny, right? The current driveshaft is fitted to the I-6 rear, and a c4 tranny.
Ok, I'll address question #2 first. The drivershaft question is hard to address because you never gave me any additional info. How did your car leave the factory ( I know it was a six_) ,but the key question is was it a stick or an auto ?
Did it still have the drive train in it when you bought it? To give A vague answer if your car was an auto and you still have the driveshaft from it, it should work unless the setup you buy is very early ( not likely) or if something was changed over the past 40 years.
Question # 1 This is a toughy, when it comes to body filler the rule of thumb is use as little as possible.
Typically you don't want to go over 1/8" thick. No matter what brand you use and how thick you go it can settle, shrink, crack or be wavy. The thicker it is , usually the worse it will look. Here we go with more questions You need to body fill because of rust?
You need to body fill because of accident damage?
How did you fix these areas, Did you hammer and dolly the metal out? Did you cut and weld in new metal? Did you just dig the old filler and want to reapply? How did you treat any rust (sanding,chemically,etc) ?
***** Most important question Can you post a picture?
Moisture is usually the biggest culprit on lifting and cracking filler, Let's say you fill over holes and you smooth it out, prime it,paint it, etc. The moisture will enter from the under side .
Let me know on those questions and I can help advise on the driveshaft and such.Later