Starting a BB Duster project

AndyF said
Yes that is the next thing I'll try. I'll put a 195 thermostat in there to see what happens.

Following.
I had hot 406 sbc in a 92 short wide gmc pick up w/ a 31x19 crossflow/2 rows of 1/1/4'' tubes that did the same thing went to a hotter stat , but it still cycled on the stat, left it that way , never any problem. ,