Newbie to hydraulic cylinder and like system builds....

So I'm no hydraulic engineer and my appreciation of hydraulic capabilities comes mostly from operating tractors with front loaders.  I've poked around on other internet venues for answers to the following, but since there are many DIY's on Permies, both in the forums and at Wheaton Labs, I opted to post this here.  Fortunately, my question will be more of a general one that others have perhaps run into when modifying the hydraulic systems on their tractors, log-splitters, skid-steers, etc.  

On a rear-steer Deere (1445) it uses twin hydraulic cylinders under the tractor to raise and lower the attachment of the season....typically mowers in the summer and snowblowers in the winter.  The open-center hydraulic system operates at ~2200 psi and a little over 5 gal/min.  The cylinders under the vehicle mentioned above are powered by 3/8" (I.D.) hydraulic lines and connectors and these will lift 500 lb implements with little effort.  The snowblower additionally has a powered chute which can turn to throw snow to the direction desired by the operator....separate hydraulic ports serve to power the hydraulic lines to the chute and these lines, running from the pump to the chute cylinder, are 1/4" instead of 3/8".  

I'm now interested in using these auxiliary ports to power a single cylinder for operating a home-brew, light-duty, limited-range front loader/pallet fork.  The cylinder chosen for the job (16" retracted length--24" extended; 1.5" bore; double-acting) was a compromise between several factors, but has 3/8" ports.  I've already 'test assembled' (not sealed) the cylinder with 3/8" fittings, 3/8" (ID) hose, and a 3/8" elbow fitting to which will be attached the quick-coupler for connecting to the tractor ports.  Here is where it gets funky.  Turns out, the size of the coupler is dictated by the ID of the the system (??....I'm thinking??).  So the coupler I purchased for my 3/8" assembly is too large for the coupler on the tractor. [In photo below, I've removed the coupler from the hose.] I've seen mention that it is okay at times to use a fluid reducer in-line with the system, but am unsure how this affects performance.  If I use a 3/8" to 1/4" reducer fitting to enable use of a smaller quick-connect coupler, thereby allowing connection to the tractor ports, will this result in slower movement of the cylinder?  ....  Reduced lifting capacity?  Will there be any adverse effects of having the remaining downstream hose, fittings, and ports at 3/8"?  Thanks in advance for all comments and insights on this conundrum!