what are the consequences of running without a thermostat? Thanks!

The thermostat question has been discussed many times, I suggest you "search" previous postings for more information.
Bottom line, the 351-C was really designed to operate with a thermostat. There is a water passage, in the block, under the thermostat that is opened or closed as the thermostat operates. A little " hat" (see photo) on the bottom of the thermostat covers the water passage when the engine is warm and the thermostat opens.
So without a thermostat this passage is open all the time and will probably make the coolant circulate poorly and the engine run hotter. Some people block off the water passage permanently, that isn't really recommended either. With the passage closed, coolant circulates poorly through the block and heads and you can get hot spots, maybe even "steam pockets".
The recommended thermostat is a Robertshaw 333-180, it has the "hat" necessary for a 351-C.

The Robershaw 333-180 is not only a recommended thermostat, it is the correct thermostat. It is identical to the thermostat installed oem by Ford, I believe the oem thermostats were made by Robertshaw.

The Robertshaw is readily available, so there's no need for anyone to modify their cooling system to use another thermostat, or do without.

Anybody have the brass bypass. I need one.

Marlin Jack has them.

Thanks George

Sickcat yes I have a NOS one (very expensive) and a great used conditioned bypass less expensive- the bypasses are almost impossible to find !
Maybe trade parts if ya have anything
thx Mike #7042

quote:

Originally posted by bossman963:
...the bypasses are almost impossible to find...

Hi Mike, hows it going?

I just want to correct one thing. The bypasses "were" hard to find. That is no longer true for Pantera owners. Marlin Jack, who is a member here, is a machinist by trade. He manufactured the dies & is now able to stamp out restrictors identical to the oem piece using very high quality brass. He was getting $40 each for them, I have no idea if the price has changed.

quote:

Originally posted by Cowboy from Hell:

quote:

Originally posted by bossman963:
...the bypasses are almost impossible to find...

Hi Mike, hows it going?

I just want to correct one thing. The bypasses "were" hard to find. That is no longer true for Pantera owners. Marlin Jack, who is a member here, is a machinist by trade. He manufactured the dies & is now able to stamp out restrictors identical to the oem piece using very high quality brass. He was getting $40 each for them, I have no idea if the price has changed.

As George said, Contact Marlin he's a great guy! pantera1974@verizon.net He'll help you out!

Curt

Hi George Im doing pretty well and you ??
thhanks for the info on Martin will keep it in mind
thx Mike #7042