[mr48chev]

The issue with Spal fans is you have to research the Spal site and find the one that moves the amount of air you need to move. All Spal fans are not created equal even the same diameter.

I haven't heard about the Lincoln MK VIII fan That is one of the things you want to do your own research on as far as CFM and measurements.

Now, I have to ask, does the temperature drop right down where you want it to be as soon as you hit 30-40 mph or so? If it does, you do have a fan/air flow issue, If it doesn't you most likely have a different issue. Unless it is super hot outside or you are pulling a pretty serious load or climbing a long grade the fan normally doesn't have much effect above 40 or 50 and my experience is that even with a suspect radiator the air flow from the truck moving usually comes into play at about 30.

Last, how hot do you feel is "too hot" or not cooling enough? LS engines aren't 235's and they operate at a higher temp than most old engines do. Meaning what temp is normal for that LS in the donor car it started and spent part of it's life in? If the car left the factory with a 205 thermostat as it's standard thermostat and you stuck a 180 in it and get your undies in a knot because it now shows 205/215 on the gauge at a stop light there really isn't an issue.