I posted this on another forum as well to increase my chances of solving this dilemma....

I am ready to start mocking up the 454 in my 91' and a local shop that does custom radiators can't add a core to the new style radiator and a custom would be big $$$.

I am not putting the AC back so I have the condensor space to use. How about piping in an additional radiator the size of the condensor and tap into the radiator inlet and outlet? Think it will work? Heck, maybe even the condensor would work.

Let's kick this around a bit as I have to solve this. These cars run hot as it is and I know that I need more cooling for the big block.

 

I think you are going to have to bite the bullet and buy a Dewitts or Be cool. Big blocks run hotter then small blocks, you are going to need a good radiator.

 

I would go the DeWitt or BeCool route, few more bucks but less headache.

 

I think if you put a large pusher fan in between the two radiators and seal up the sides and the top and bottom, you got a good thing going.

 

Cooling on C4's is marginal at best , with a BB you want as much coolant as possible to act as a heat sink.

 

I would pull off the shroud and take out the stock radiator and a/c condensor. Now, measure the space you've got. Go to a hot rod shop and see what Moroso or other good radiator they can find that's close to your measurements and has the inlet/outlet close. I know this works. A buddy of mine did this on his '86 when he built it into a 383 minirammed motor. He paid WAY less than I did for my custom Ron Davis one. Once you get the radiator that comes closest to your size without going over (just like "The Price is Right") you can use some good chunks of rubber to carve out nice shims to secure it inside the shroud.

 

Don't waste your money on the radiator solve the real problem air flow. I did what you are thinking about doing already. I had a 5 row staggered core aluminum radiator custom built, 25" oil cooler, custom air dam built at the radiator air inlet, 2 black magic fans 1 pushing 1 pulling, water wetter, 195 fan switch, 160 thermostat and if I turned my a/c on at air temps over 80 degrees I would still see engine temps over 230 and climbing until I turned the a/c off. at 90-95 degree air temps I couldn't drive the car because it would hit 230 without the a/c on. So after spending $1500-$1800 I still had a temp problem and left 3 radiator shops scratching their heads. I spent $35 at the junk yard for a 88-93 ford taurus 2 speed fan and $160 for a 140 amp alternator. now at 105 degree air temp with a/c on idling in traffic the highest temp I have seen is 207 and the fan comes on at 205 with a 195 thermostat. The 140 amp alternator is because this fan pulls 70 amps at start up in high speed and I think it pulls 35-40 amps constant running in high speed. google ford taurus fan you will find plenty of info if not let me know and I will send you pics of mine and a wiring diagram

 

Got your reply on the DC!
Thanks