This may be a silliy question, but......on my 71, originally a 350 engine, there is not what looks like a traditional overflow tank for the coolant. The radiator cap is actually on a metal tank on the passenger side fender. Is this factory or something else? If factory, how high up should the coolant level be when cold? Since it's metal - no way to check level when its warm...I like my face unscalded, thank you...

Yep, that's factory.  The metal tank under the right side fender is actually the expansion tank.  And no you do not want to open that when things are hot...!!!  My '70 has the same setup as you do and the cap has a pressure release lever on it if I HAD to open it when the system was hot.  I'll have to look again to be certain but I'm pretty sure there is also an overflow hose coming off of the expansion tank.

When the system is cool I keep the coolant level at about half full in the tank.

thanks Jim!

Yep, mine's missing as the PO has put a nonstandard 3core radiator in with an expansion tank on the radiator.  Fits in perfectly and all the shrouds fit up without a problem.  Car runs at around 190-210 in the middle of summer so am not sure if I will change anything.  leaves more room under the fender to get at the wiperdoor vacuum switch.

 My '71 has no overflow tank, just a short metal tube below the radiator cap that I guess used to go to a tank. Where exactly did the tank used to mount and until I can get one, should I run a hose down to the bottom of the radiator, or does it matter? I don't really see any signs of it leaking under the hood.

There is an overglow hose coming off the expansion tank. If I remember correctly, it says on the end of the tank to fill 1/2 when cold.

Was this tank standard on all 71 vettes? Corvette Central catalog leads me to believe that the tank is only on aluminum radiator equipped vettes. So the next question is, are all the radiators aluminum? If no, how can I tell if it is aluminum? What radiator cap do I get (existing is looking pretty ragged and there are no markings on it to go by).

I'm pretty sure the tank was standard on all C3s, especially the early years but can't say for certain.  I'll take a peek under the hood of "The Toy" tonight and see if there are any markings that are readable and let you know. 

If you don't have an Assembly Instruction Manual (A.I.M.) for your year I'd suggest adding one to your garage library.  Also add the repair manual by Chilton's and/or Haynes.  Lots of good info on capacities and specs in all three.

On my 74, the overflow tank has a line at the bottom.  I'll say about 2" from the bottom.  I thought it was a little bit low last time I cleaned that tank. I also found out that my hose in the tank is not original a a little longuer than it should be, so now I put about 4" of mix in it.

In '68 the base 327/300HP engine had no overflow tank, just an overflow hose that ran from the radiator cap to the ground.

The 327/350HP car had the aluminum oveflow tank, & the radiator had no cap, it was on the aluminum tank.

I'm not 100% sure about the big blocks.

For reference, take a look & any '71's for sale (E-Bay, CCTOL) & see what type of setup they have.

Anthony