http://www.stewartcomponents.com/index.php?route=product/category&path=61  
304 - 306 are modified   307-309 are non modified. choice of three temps  your choice.
stuey 

Or the Desert Eagle.
I know NAPA does two versions of thermostats for the Yblock. I have the more expensive one which I think has a larger opening.

Well, if it’s the same plant that makes the Uzi, they’re probably fine.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I'\ve run across another brand of thermostats that have a wide mouth.  Brand is MotoRad.  Made in Israel  ( I assume better than China)


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Here is one thread showing a picture of the holes.  Many more can be found by using the search feature with thermostat in the "search discussions" field and greenbird56 in the "search username" field.

http://forums.y-blocksforever.com/Topic131572-1.aspx

Milodon, and Stewart components sell a Made in USA thermostat.  The Mr Gasket is a Chinese copy.


Lawrenceville, GA

Big block Mopar - Mr. Gasket #4367

https://www.ctci.org/gilsgarage/Thermostats2.php

That's for 180 degree F. Thermostat. 160 doesn't make much sense.

I remember there was a discussion one time about creating a high flow thermostat by drilling a couple holes, but I can't remember the specifics on that. How many and where? As an alternative, I think high flow (160 degree) T-stats are being made, but you know how it is these days when you go into a parts store, they need to know the application before they can find anything. I believe Chrysler/GM makes one. Anyone have a make and or part number they can share?

Thanks!

  Ron Lane,  Meridian, ID