Hey everybody

did the 2v truck 360 and 390 intake manifolds use a smaller diameter thermostat and housing than the 4v manifolds like an S code or performer RPM? The thermostats that I"ve been able to buy are always much smaller in diameter that the recessed area in my water neck. I can't seem to keep the thermostat perfectly centered when I install it, so I have significant coolant flow through the radiator way before the trucks warmed up- so it often doesn't warm up at all. My truck had an S code manifold on the 360 when I bout it, and I now have a performer RPM on the 390, so I've never seen one of the original intakes for the truck engines.

Thanks

 

There are two sizes of t-stats, I don't remember the issuing engines, but it is pretty easy to look at and tell. Just go back to the parts house and ask for the large one.


John

 

It sounds you have a earlier thermostat housing for the larger stat. Ask for a thermostat for a Mopar 318/440. It's the same dia (63 MM) as the larger FE stats. Most part houses only know/list the smaller one. NAPA is a #191 thremostat 180*. Just ask for the right temp range you need.

 

As I suspected. Thanks Joewilker and FFR428! I love this forum.

 

Exactly right. I haven't been very impressed with some of the people I meet working in parts stores lately. Seems like back in the 60's & 70's those parts guys knew their business. Last Saturday I went to NAPA to get a thermostat for my new build. (390 Edlelbrock RPM intake). The guy sold me the small one and I said, "I think I need one bigger around than this". Some young kid working the counter looked at it and said, "Look up the part number for a 440 Mopar". Works just fine and available in a 195* variation. My faith in the coming generation of gearheads has been restored.