Hello all, this is my first post although I've visited your site many times while working on my 1956 F100. I apologize up front because I know this will be a long post, but if this information helps somebody later on, it will be worth it. First off, my truck: I'm the luckiest guy in the world to get a hand-me-down 1956 F100. My great-great grandfather bought it new towards the end of 56, it was built in September of 56 according to the date on the heater box. It is an "original" truck, it has never been wrecked, still retains all its original sheet metal, and is still in its original color (repainted in 1973-I have one of the empty paint cans that is dated). It has the original 272 and 3 speed column shift trans, but the rear axle is not original to the truck (out of another 56 and same gear ratio-3.73). Original style exhaust, except for a glasspack. 1957 4 barrel intake manifold from a 292 installed to run a 600 cm Holley with manual choke. Carburetor mounted backwards to align choke and throttle linkages correctly (works great!). Drop/forward front springs, rear lowering shackles, centerline 15 x 8 wheels, stock steering, stock 4 wheel drums. Drive the truck often. Runs, drives, steers, and stops great. Added seatbelts for the kids.

Original radiator finally started leaking bad enough it needed replaced. After pricing, I decided to buy an aluminum radiator, which was manufactured by KKS (China). All aluminum radiators I found were advertised to fit 53-56 F100 trucks with y block engines. I also planned to install a thermal fan clutch and new fan blade, ditching the rigid 4 blade factory fan, and replace the water pump with a new unit while I was in there. I knew some small modifications were in store due to fan spacing. I had planned to reuse the factory shroud setup, and chose the KKS brand radiator due to the die formed tanks to retain some original looks once I painted it black. I received all my parts and started mocking up the fitment.

*Disclaimer*: I already know most people would plan to install an electric fan setup when using an aluminum radiator in these trucks, and the holes pre drilled for the shroud are also used to mount the electric fan and shroud combo. This was not my plan. The radiator add did not mention that stock parts would, or would not fit.

The new radiator came with pre drilled holes for mounting in the truck, and holes to mount the shroud. The first problem I encountered was the mounting holes for the shroud were wider apart (from side to side) than the holes in the shroud. In theory, the left and right sides of the shroud would need to be stretched out about a 1/2" for all the holes to align. Not the "end of the world" type of problem. I mounted one side of the shroud to the radiator and moved on for mock up. Installed 2 bolts thru the new water pump, and installed the radiator in the truck to start checking new clutch and fan setup. Radiator mounted up to the core support without much effort, albeit there wasn't any room for play left in the bolt holes once all bolts were run down. Went to install the new fan and clutch, and that's when things turned ugly. The new fan blade (18.25" - stock is 18") bottomed out on the shroud and I wasn't close to the water pump. A measurement showed the clutch hub was about 2.25" to high, obviously keeping the clutch and fan from lining up. The upper hose (pipe) would also not touch the thermostat housing in its current state (as it would with original radiator) .Tried searching the interwebs, but couldn't find any similar situations (back to my disclaimer above). I re examined the add for the radiator and didn't find anything in the fine print there either. I know the 56 model is unique in many ways, but since the front sheet metal, including the radiator support are the same for 53-56, I still couldn't understand the problem. I finally came across some information that told me all (or most?) 53-55 trucks came with a different water pump that provides a boss for a "high mount" fan which moves the fan and shroud opening higher up in the engine compartment. The 56 model brings the fan mounting down to directly on the water pump, which brings along other exclusives for the 56 truck: the radiator, the shroud and the water pump (unsure about the fan blade itself).

The 2.25" too high brought other challenges: the lower radiator tank only had 3/4" clearance to the core support, the shroud couldn't be dropped farther down the radiator due to lower hose port and drain cock on the radiator, and the radiator mounting holes (pre drilled) were obviously going to be in the wrong locations. I looked at electric fan options, but ultimately decided to press on with my original plan. Originality is already out the window, so I pulled everything back out and got out the grinder and cut-off wheels. I cut/ground most of the rear facing channel off the core support, grinding it completely off end the lower bends so the lower radiator tank would clear when I lowered the radiator. I then cut 1.25" slits in the corners (at 45 degree angles) of the shroud so I could spread both mounting edges out to match the mounting holes in the new radiator. Took it to my good buddy that welds to have the new slits sewed back up to prevent issues from cropping up later. I also had to grind the "lip" off the very bottom of the shroud so it fit the radiator better. Also had to take a hammer to the bend around the lower hose for better fitment too. After all that, I moved on to dropping the new radiator farther down in the engine compartment. I ground plant off the core support, I then used wood shims to bring the radiator up small increments to finally perfect the alignment of the clutch and fan into the shroud. I could reuse the factory lower attachment (welded) nuts by drilling new holes in the radiator mounting flange that matched up. I had to drill new upper mounting holes in the core support to match the pre drilled holes in the radiator. I then had to use a flanged nut, as it wouldn't slip through a box end wrench when installing the upper attachment bolts. There is no way to get your hand in there without dissembling the front of the truck (too much rust and rot, not going to happen).

Another issue I came across is the new water pump actually replaces the car version water pump, and I had to shim my water pump pulley out 1/4" for proper belt alignment. I don't know if that should be normal or not, or if that issue existed before and never noticed. Either way, it's fixed.

I still don't have the truck fully assembled, we took a short trip for spring break, and i'm waiting on my heater core to get finished at the radiator shop. But when I'm finished, I will report back here with a list of all the part numbers I used, and how it turned out. I'll also try to include some pics too.

Again, so sorry for the super long post, but if it helps anybody in the future, then it's worth every word written. Please feel free to correct anything I assumed or wrote here, as I know I'm no expert on these trucks. I also know there are new replacement radiators out there for the 56, but last I saw they were in the $500 range. I havent spent that with the new radiator plus in all the other upgrades i am doing, and i wanted to see how I could incoorperate a clutch fan into the system on the cheap.

Happy motoring y'all!
Jon Bowman