Sounds like a good alternative to supplement the cooling,rather than trying a new radiator.The radiator I have is from a 6cyl w/a/c ( 3 cores),and I had it reconditioned before I put it in.I was just looking at Griffin radiators,thinking I should bite the bullet and get one,but apparently that might not be the answer.I like what you did because you can control it when you need it and you still have your original fans.I am still in the break in period with the motor amd will keep an eye on it.
Thanks