Re: 40 below additive does it work?
I had the same issues with my 383 Chevy in a `62 CJ5 last summer. I know of Redline's water wetter and 40 below, from the race track. I work on some NASCAR race cars during the summer here in Denver. I had tried everything to cool this thing down, a steel racing fan, additives, electric fan in front of the radiator.....etc. The thing that I found that finally cooled it of was to drill 2" holes in the bottom of the inner fenders. If you have everything blowing hot air over the engine and no where to exit it will keep you temps smokin hot. This was proven to me by a friend who has a small block Chevy in his CJ, but ,had fenderwell headers and took them off. He states," It never runs over 175." I looked at his fenders and there they were cut for the headers. But, if you don't want to do that try CRC's "Engin Kool" it comes in a quart oil can, and can be had for about $6.00 at NAPA.
p.s. my radiator is a 2 core out of a `64 Impala modine #281