I'm having trouble finding a thermostat housing for a 69 olds 442, 400ci. The parts stores i have contacted only seem to have one thermostat housing to do both A/C and non A/C cars. In the service manual (section 6k-8) it says that there are two different housings, one for a NON A/C car which has a .542 tapered bypass outlet hole, and one for an A/C car which has a .410 tapered bypass outlet hole.The reason this is important is that excessive pressure may exist in the bypass hose if a standard cooling system outlet ( large hole ) is used on cars equipped with air-conditioning or heavy duty cooling, due to different water pump pulley ratios. Can you still get the right housing and if so who stocks them?
Thanks for any info.
Cheers

 

Probably Fusick's or Supercars Unlimited.

 

The 1970 Chassis Service Manual says the same thing, that there are different thermostat housings with different size outlets. But if you look at the 1970 Engine Assembly Manual, there was only one thermostat housing used.

Maybe 1969 DID have more than one housing (I don't know), but based on 1970, I wouldn't worry about using one with the wrong outlet size.

 

Thanks guys for taking the time and commenting