I am doing a frame off restoration of a 1970 SX Convertible.

I have seen several other frame off restorations and notice several inconstancies.

Does anyone know if the underside of the car was painted the body color from the factory? or is it supposed to be a semi gloss (what percent gloss) black? If it is not the body color, how much over-spray of body color should be on the underside?

Also, are the hood hinges black with gray phosphate springs, or all gray phosphate or all black?

Are the coil springs gloss black or natural metal?

Is the front sway bar natural metal or semigloss black?

I ask because I have several pages of GM A-Body restoration guidelines from different sources and they are inconsistent.

Please, I do not want opinions, I want to know the facts as to what paint/coatings were correct on a 1970 Cutlass from the factory.

If anyone has a COMPLETE detail of the paint and coatings used on FACTORY 1970 Cutlasses, I would love to be informed.

Thanks,
Dan

 

You will have to find out exactly what each assembly plant and Fisher Body plant was doing at the time your particular car was built. You will also have to find out what the suppliers were doing. Things changed from week to week, shift to shift and person to person is why there are so many inconsistencies in the available documents. You may find two original, unrestored cars from same plant built at different times and details will be different between them.

Lansing assembly was probably the most consistent; Southgate did a lot of things their own way.

My advice is not to go too **** about stuff like this. There were process and production changes thruout the year.

If you're ever on ROP, contact Dave Heilala (daveh). He was at Lansing when these cars were built and knows as much as or more than anyone I know of.

 

Thanks,

I do tend to go overboard on details a bit. Knowing that the plants were not consistent themselves does give me some leeway. I do not have the trim tag in front of me but I do remember from the engine and transmission build that all of the date codes ranged from August 14, to August 28 1969.

Thanks again,

Dan

 

Does anyone know if the underside of the car was painted the body color from the factory? or is it supposed to be a semi gloss (what percent gloss) black? If it is not the body color, how much over-spray of body color should be on the underside?

The floor pan could be body color in part, but at least part would be semigloss black. You are pretty much safe to use black between semi gloss and semi flat "anywhere." that being said, some stuff was not painted, like the driveshaft, tranny. I have seen painted rear brake backing plates, with the front ones bare metal (with some black out on them--black out being the GM nasty asphalt based spray like an undercoating). Tranny crossmembers were generally bare metal, and added on stuff like brake cables were gray plated not painted.

Also, are the hood hinges black with gray phosphate springs, or all gray phosphate or all black? They were a medium dark gray phosphate, but I believe the springs could be bare or black--pretty hard to find evidence these days but what I have suggests they were bare.

Are the coil springs gloss black or natural metal?
most were bare metal, but you could get away with semi gloss black.

Is the front sway bar natural metal or semigloss black? bars I have seen including from GMPD were semigloss black.

 

Take a rag with Lacquer thinner and wipe off some some the crud at various areas you are interested in. That should give you a good idea. Simi-gloss black will look good under any car - if it stays there long.