472 cadillac engine swap

[80goldenburb]

Since the high heat light never came on until 265 in a stock caddy the issue of over heating most likely would never be a problem.

Its like any other GM engine. Keeping it at 210 is the best way. 265 is the factory setting when the idiot light comes on with the annoying buzzing sound. Had that happen to me in my 76 fleetwood brougham.

Told I was turning the engine too high(3.73 gears in truck) wasn't.

Hate to break it to you but that was most likey your culprit. 3.73 and higher are for the screamer chevy engines. You should have swapped gears to 3.21 (if you have the 14 bolt FF). That caddy has lots of low end torque and does not like to rev high for long periods of time. my '76 weighed as much as my 80 sub 2.73s with 410 lb ft from the factory and it got up and went at 2500 rpm

Also, have seen a guy with a '71 Eldorado tow a 25 ft travel trailer and told me he had no problems minus going uphill where it crept to 225 ish. But here's other guys who tow also, they are not having the issues you are having.
http://forums.cadillaclasalleclub.org/index.php?topic=126005.0

Cooling system wasn't totally the same as any other gm engine at the time. Return from the engine came out the front of the block in caddy's and not out the intake as in other gm engines(only one I can remember with a dry intake).

yea forgot to mention there isnt flow on the intake.

To this day I think the problem was water staying in the rear of the block(water had to go into the block, up into the heads, and back into the block before going out to the radiator). Later engines moved the heater hose from the front to the rear of the cylinder heads.

True to that, another to add to the issue. I might drill mine just to be safe

Wow! That surprises me. I'd would have guessed it was as heavy or heavier than a BBC. What did Cadillac do to save weight?

Cadillac had alot of nickel content in the blocks vs chevy being completely iron.