Thermostat Uh-oh

Well I picked up a thermostat for my 85 VF700F and went with the parts numbers I got from Jamie Daugherty. Turns out the stock thermostat is shorter and the new ones have some extra part which I cant use. (still fits in the housing but the thermostat cant open properly).

Did I do something wrong? Also I Boiled the original thermostat and it still seems to be working so if all else fails i'll have to continue using the old higher temperature one.
pictures comparing the thermostats below

 

That is quite a bit different in height. I still have the original thermostat in mine also. Before you put it back in, drill a 1/8th to 3/16th hole in the flat area. It will keep you from getting an air pocket when first refilled with coolant or anytime.

 

Whoa! Yeah, the new part should not have had that additional section. Not sure what's going on, it's been several years since I bought one of those t-stats. I wonder if it's just a design change, maybe just for that part number. Can you chop off that extra part?

 

Well, took that thermostat back to the auto parts store and got a thermostat in the mail from Autopartswarehouse.
Turns out the brand of the thermostat it had (NTC) still has some that look just like it with minute differences. I picked one of theirs up that's a 170 degree for a 1974 Nissan/Datsun 710.
The outside rim is just a fraction of a mm bigger all around so im just going to grind it down to fit in the housing. Other than that it seems to be an extremely good replacement compared to the stant,murray,etc auto parts store brands. (They even had a different opening mechanism when these have a big wide platform.
and it has a hole in the platform that opens probably for air bubbles if it works well enough.

 

Thanks for the update, I went to buy a thermostat today using the numbers Jamie had posted and I got that same over size one you bought, looked through their books and couldn't find one the correct size.

I'll go back and get one for a 1974 Datsun 710, thanks.

Do you still have the NTC part number?