A few months back, I asked about radiators for my LS1 firebird. Trying to keep cost down, I was looking at a universal radiator. A member suggested AFCO. And others ask for me to get back with what I found. So here goes, I looked at their site and I am thinking of going with their 27.5 X 19 X 3 double pass radiator. The price was right 224.00. Being it is real close, other that thickness, to the stock dimenions, should be a real easy fab to install.
My only question, LS1 motors have steam vent lines coming off the cylinder heads. These lines go directly back to the radiator just below the radiator cap bottom seal area. Just above it is the overflow outlet that sits between the top of the cap and the bottom seal area of the cap. This AFCO radiator only provides for the overflow line. It has no provesion for the vent lines. Will I need to drill and weld in a vent line outlet into the side housing? And does the height of where the vent line goes on the radiator critical. I now higher is better.
Any thoughts on the steam vent issue would be apprecated.
Ed
Something else came to mine, do I need the temp switch outlet to run anything in the computer other than fans? I will be switching to a small manual one for cool down laps.

Call Afco, tell them what you need and they'll generally build it. I had mine built with an internal oil cooler and a location for a coolant pressure switch to turn on an Autometer Pro Lite if I lose a radiator hose or otherwise lose pressure in the system. Anything you want, they'll generally do. And, the prices are reasonable.