Running hot

I have a 360 bored .030 less than 2000 miles,tti headers, cammed, etc. The cooling system is 17" x 22" 2 core stock type radiator, stock pump, 50/50 antifreeze and water. I was running a clutch and stock fan no shroud, no over heating... now I run a electric fan with 3650 cfm still no over heating.

Now your cooling system sounds like no difference than mine before I changed to electric fan so this is really a strange thing.