I am making some mods to my floor pans and need to rebuild some portions; what gauge or thickness sheet metal do I need to order / use to be consistent with original metal? Easier for welding right?

Thanks!

I can't speak for that timeframe but in this day and age all the sheetmetal is spec'd by the auto manufacturer to provide the necessary strength at the minimum weight (read cost !!). This means that standard gauge thicknesses are thrown out the window. All steel is rolled to those specs. So if that's how they did it then then you're going to have a problem matching it exactly.

This is also why much of the replacement sheet metal is not the same gauge as original. The reproduction companies can't afford to buy in the quantity required by the steel mills to run a custom gauge. Also to keep costs down they could be buying overruns of a "close" gauge.

I doubt you're going to run into that. 1966 was in a different millenium. CAFE meant a place to get coffee and a piece of pie.

I'd go with 18 gauge.

R.