I typed a 1 instead of an I
I relooked at the number....upon closer inspection the number is CI840392
I'm pretty sure Cadillac didn't use an X style frame.....but I'm not 100% sure. If anyone can narrow this down that would be great.
I am also trying to figure out whatengine I have....the casting number is 3970010 on rear of engine dr side....on the pad in front of the pass. head is T5F505426 V1218TYZ pretty sure it's a chevy 350 but thats all I can come up with...I would like to know the year 2 or 4 bolt main ect.