Is the 261 in the truck..... as it been running in the truck with the 261 and the existing 2561 water pump??????
Reason for asking..... the overall lenght of the 261 is looooonger than the 216 and the water pump needs modification.
Your 261 has a water pump partly inside the block and located higher on the block........ unless the radiator has been moved forward 3 to 4 cm......or the total engine moved backward.
Check the technical section of the forum library ofr detailed info.
Basically you have to remove your 261 pump and replace it with a 216 water pump with the aid of an adapter plate...... sounds complex but one step at a time and you get a finished professional installation.
While doing the plumbing check your thermostat...... worth getting a new one..... I run a 165 degrees Fahrenheit has the engien compartment on the earky cab 11 is very HOT.....
Care will be needed to insure your 3 pulleys align up properly...... and that they all match teh same width belt ....... early belts were 3/4 in. but your truck crankshaft belt will be modern and take 1/2 belts. in some cases we re install the 216 harmonic balancer to maintain same rpm of pump to crank ratio.....prevents cavitation and over heating.....
Here is a photo of my valve cover...... its a 216 valve cover made to fit the 26i with the military crankcase mini oil bath air breather needed for the PCV valve to function properly.
