Upgrading my '70 Cutlass from a 350/TH350 combo to a 455 with Tremec TKX 5 speed. Target on the engine is 450 hp. The radiator was the standard 2 row. I have this aluminum Champion Economy Series 2 Row Core (EC161) I picked up a while back and wondering if it will be enough to keep the 455 cool. The specs say it's good for 400-600 hp. Will an electric fan be needed or preferable to a pulley mounted fan?

Also wondering about the radiator cooler fittings. Is this radiator even suitable for use with a manual transmission, or does the Tremec also require the cooling?

 

I would try the stock radiator with a fan and shroud first. I run a single row aluminum, no shroud, and a flex fan.

 

Unless you get good electric fans that draw amps and move serious CFM, they will perform worse than the stock set up. Do you have a shroud? Is the fixed a 4 blade or a 6 or 7 blade clutch fan? Try the stock rad, that Champion is a slight upgrade probably at best, it may not be any better. With the OD, either rad might be big enough cruising down the highway. Just make sure the fan set up is up to snuff either a 7 blade heavy duty clutch and shroud or factory or something like Derale electric fans. A Robert Shaw high flow and closed impeller water pump might help a tiny bit ad well. Good luck.

 

Yes, the radiator is OK for a manual trans application. The factory replacement radiators on my manual trans vehicles have one, it's just simpler for companies to make one radiator for both auto and manual applications. And no, your manual tans doesn't require an oil cooler - it doesn't have a pump to push the fluid through the external cooler.