Anyone have any experience or thoughts about the high volume water pump and high flow thermostat like the one in Classic Industries catalogue? Increases flow up to 30% and reduces temps by up to 25*. Would this be good for my 350 w/ stock radiator? ( no racing, just cruising) I just had stock gauges put in and I notice I'm running a little warm...not quite to the yellow, but close in heavy stop and go traffic. Any input would be appreciated.

And another question. Everything I've read says the radiator should be filled to about 2 inches from the top...
On the 68 there is no coolant return tank, just a hose that dumps coolant on the ground when things get toasty. Kinda messy. So, I bought a cheapie autozone return tank and hooked it up. Put a little coolant in there, to about the "add" mark, but I'm really just using it as a "puke tank". However, when I check my coolant level in the radiator in the morning, its filled all the way to the top. (I'm using a 15lb radiator cap.) Is this affecting the circulation? It is, however, keeping the driveway dry!

Nothing wrong with high flow water pumps or other heavy duty or performance parts when used correctly. By that I mean if you have a poor condition cooling system and put a performance water pump into play it's gonna cause other problems to surface. The whole is only as good as the weakest link.

If you read through old cooling system threads you'll see I am quick to remind folks that the stuff that came from the factory on our old cars did the job very well over the years when it was maintained. That said it's my recomendation that you isolate the cause of the problem. Getting warm in stop and go is indicative of poor air circulation through the rad core. If temps are fine crusing down the hwy the core is most likely ok, look at your fan, shroud and possibly any obstructions in front of the rad core. It could also be an indication of not enough initial timing. Your second post leads me to think your cap may be bad unless you converted it to be a perge and recover cap when you added the overflow container.

Also factory guages are known to be inaccurate and unless you have had them gone through you may want to find an IR gun and verify their accuracy.

Thanks Dennis,
I didn't know there were specific purge and return caps...I guess because the car never cane with one initially!
I will have the temp gauge checked out...the car doesn't seem to have any "hot running" symptoms. And when I was just using idiot lights, it never came on. No obstructions to the air flow, core. Fan looks good, not electric, plastic or aftermarket.
This is just another example of buying an old car thats been gone through by who-knows-how-many-hands. I was thinking of replacing the pump and thermostat because then I would know exactly what I have. Thats why I was curious about the high flow stuff. I just wanna do it right the first time.