pass1over

just got done swapping a harness and ecu out of a 91 mustang on to the stroked 5.0 in my 66 (started life as a carbed engine). Im pretty sure I had a 180 degree thermostat and put that back in when I put the new manifold on.

Will a lower t.stat not allow the ecu to go into close lo0p mode? Should I put a stock 192 degree t.stat in it instead?

Back-in-Black

I run a 160 in my 1989 5.0 and have no problems. If you live in a colder state and still have a heater I would go with the 180.

pass1over

i suppose its a colder state, kentucky, its colder than florida ... haha

no heater, and nothing really stock about it. Only "stock" 91 parts I kept was the ecu and harness

mattdel

you have no problems, yet. Unless you're carbed. If EFI, stick with 180 or 195. Closed loop hits at around 180. Assuming the car will run an average of 10 degrees hotter than the installed thermostat, with a 160, you'll never hit closed loop, and be running rich full time.

Timspony

...Just go with the 180*

Back-in-Black

Have done it with my 87 GT, 90 GT and now this one and never had a running rich problem yet. You are most likely more of and expert than I am but I was just giving my experiences.

AdderMk2

I run a 180° in my car... and I still dont go into closed loop... so I might change up to a 192°

Liquid_02

I run a 180. I don't let my car into closed loop anyway... Don't have the O2's in.

86HOGT

I believe closed loop begins at 172 ish?

xxxmustangtxhc

i run a 160 on my car and my g/f car i have been using a 160 for 4 years now i dont have any problems and im from South Texas...