For more capacity, find you a small turbo intercooler mounted under the front in the air flow and run your coolant through it first then into the radiator.
When I changed to aluminum radiator, I had to build a lower radiator hose tube to reroute around the oil filter housing since the new outlet was different then the stock one. Using exhaust pipe elbows I was able to route around where I needed to go. This tube alone added 3/4 of a gallon of coolant and the new radiator added 1/2 or more of a gallon. It still heats up normally, just takes long to get all the coolant hot.
