If any of you has a '69 ZL1 COPO or '69 COPO 427, would you please tell me what the GM numbers and "B" code are cast into the thermostat housing? thanx, George

 

Do you want to know what they should be, what to look for? or to verify what you already have?
The part number for that is the same as the RPO Z-28, 387760. It was used on all 69 V-8's.
I have no idea if there is a 'b' code on it or not.
Hope this helps.

 

I thought that it was a cast iron curved housing like on the Corvette's. Part numbers 3711268 and 3827369. And they have a B1, B2, B3,or B4cast by theGM part number.

 

Did the Z/28 have a 3711268 cast iron housing on it?

 

Checking my books and all I could find about the thermo housing is the aluminum ones and that the Z28 and COPO were the same numbers. The books could be wrong though, alot of different authors and stuff.

 

Thanx, I've seen the cast iron housing on a'67 Z/28 engine. But I couldn't see if the number was 3711268or 3827369. If anyone has a '67 with the cast housing, would you please give me the number?