...Roger...

That's scary when they start spraying dot 3 everywhere. I'm sure there are many others this has happened to (probably to embarrassed to admit it)and if they had factory paint they had damage.
I use less than 8 lbs pressure , probably closer to 5. I basically use the bleeder as an endless supply of fluid,then I hand pump the master cylinder when I want pressure. This keeps the high pressure IN the system where it belongs.

The NAPA adapters are an option but I think the Motive adapters are fine when you use a clamp and reduce the pressure.

Hardway

I had one of the Motive bleeders and have experienced the same results as the OP and others. I ditched the chain and hook clamp and used C-clamps as well. Looks the air powered systems are a better way to go. Has anyone used any of the two below? This appears to be the kind I see shops using.

https://www.napaonline.com/Catalog/C...282465013&An=0

http://cgi.ebay.com/ebaymotors/Brake...item5199d54269

...Roger...

Those are vacuum bleeders,not a good choice IMO on vette brakes.

tonak

I might try the motive again, but I did place speed bleeders on the brakes and personally I think they are the cat's meow!

...Roger...

I found a shorter pump for mine so I can put 48oz in without the fluid touching the pump and aerating it.

Hardway

Can you tell me why this is Roger? I know our cars have 4 piston brakes but I figured using a quality bleeder of any type would be good.

...Roger...

If the calipers have the factory type seals (not o-ring)the vacuum types will suck air past the seals into the caliper. The factory seals are great holding pressure from within but they just lay down and allow air to pass when there's a vacuum inside.