Howdy EddieJ:
FIRST, you have to decide what you want! Restore? Restomod? Street Rod? What is your budget? What are your mechanical skill?
While you're fleshing out your plan, start with a good assessment of what you have. A '60 Ranchero will most likely have a 144. 170s made their way into very late '60s. Check the casting code on the top of the intake manifold behind the carb. C0DE-A= 144. C1DE-A=170. In either case you will have solid lifters and adjustible rockers. Most likely the engine could benefit from a good valve adjustment. If your stock 144 is in good mechanical condition, here's some ideas. What tranny is in it?
A good electrical tuneup with new points, condensor, cap and wires, with a good internal cleaning of the distributor is a great idea. After all that is done set the initial advance at 5 degrees more than stock settings call for. The Petronix Ignitor is a good upgrade- the Petronix II is better. Either will eliminate points and all the periodic maintainance that goes with points.
The '60 144 came with a Holley Model 1904, with a cfm of 130. While the Holley 1904 is a cute little carb, some with a glass float bowl, it was designed to be very miserly. Most likely it will require a thorough cleaning and rebuild kit. That's cheap and easy.
An upgrade to a 170 Holley carb will jump the cfm to 150. That's enough to notice. A 170 carb in '60 is a model 1904, for a '61 it will be a model #1908, for a '62 it will be a model #1909. All are very similiar and all 170 carbs are rated at 150 cfm.
Exhaust should also be an early consideration. Any improvement here will be an investment for the future regardless what you finally decide. A '65-'66 exhaust manifold is a much better manifold than the '60 144. It will have a donut seal/gasket, larger volume and a 2" outlet. That along with a 2" exhaust system, with a 2" turbo type muffler will be adequate for all but the most extreme future power mods. This mod will pay dividends whether you stay with the 144, or jump to a 170 or a 200.
The ultimate sleeper 144 could benefit from a '65-'69 170 head. It will easily bolt on to your 144, but it will have larger valves, larger intake manifold volume. It will likely have a 52 cc chamber. Your 144 head will likely have a smaller chamber volume. We've measured 144 heads all the way from 44 ccs to 51 ccs. So you must mill the later head to maintain a good compression ratio. Read the sticky post at the top of this forum about gasket thicknesses and their effect on CR too. Maintain your adjustible rockers and pushrods.
Now, after all that, know that if you decide to go with a later 200 and trans, which is a good idea for all the reasons mentions above, you will have to deal with some steering/pan clearance and trans mount issues.
Hope that helps.
Adios, David