Big block cooling help

[towrecker]

Well what I have is a 1963 c30 tow truck , with a 427 tall deck stuffed under the hood , I also have A/C ...I am running a NOS harrison 3 core radiator with 16 psi cap, new heavy duty clutch fan , with I think a 7 blade fan , on say an 85 degree day it will want to will run up in the 215-220 range without boiling over , if she is left PTO engaged , and A/C on for over 5 min , she starts puking , so my thought is not enough radiator , and I think I am right , I have thought of trying to find a 4 core as I know they used to make one for our trucks , but a friend brought up the aluminium radiator idea , does anyone have any advice here , I have never fooled with an aluminium radiator on anything this old , everything now days is , I have seen some good deals on them on ebay , any horror stories on the ebay rads ? I would think it would be hard for manufacturing quality processes to really effect cooling , fit , finish , and maybe a leak when you put it on the truck maybe , I am looking to cool this beast down , if it over cools at this point I would be happy , as this truck has the holmes 500 split boom bed on it , and I don't use it daily , but it really is useful when someone plants their car in a crazy place , and I want it to be able to fast idle for 20-30 min without my horn blowing (over heat/oil pressure warning modual) or antifreeze puking everywhere , as the cops seem to get pissed over that any advice , links , radiator sources ect will be appreciated ...also I know for a fact it is not caused by the engine having a defect of any kind to rule that out , truck runs at 200 moving at any speed it also has dual 195 stats in it , and I just assume my gauge is off by 5 degrees as they almost all are a bit off I have found over the years ...ok I will shut up now