Hello Barry,
And welcome to Club Cobra...I have only been here a month or so, and have learned more than I knew in total before about cobras and related issues. This is THE place to be, and most of the members are very helpful and truly interested in this subject. Many are also goofballs, but we still let them visit
The engine fitting issue is of course related to which manufacture cobra you choose. My cobra is a West Coast, larger than the original, with many modern safety and chassis features. The original design/dimensioned cars are a wee bit tighter in certain fitting areas. But the big block Fords certainly will fit.
Generally, you will have to do hood mods, larger scoop, etc... if you go with anything larger than the oval cobra air filter housing, with the stock 1 and 13/16 height filter element. I am having a stock height (1 and 13/16 inches) K & N element installed in mine, as the stock paper element is too restrictive. Some have told me that 40 horsepower may be at stake! Ask those with your particular cobra make, what the max air filter housing is for your motor size. The intake manifold and single/dual carbs may relate also.
Headers/pipes...there are several companies out there that make nice aftermarket pipes for every common cobra make/application. Options include: Painted pipes, ceramic coated pipes, chromed pipes, and stainless steel high polished pipes (SS was my choice) I chose the SS because it can be cleaned up easily if it discolors, it will not easily rust (Yes, SS CAN rust, just not easily, or much) My builder is also using "header wrap" which is like a bandage for the headers, to keep engine compartment heat down, and channel it out the pipes instead !
I am not an engine expert, but the main difference between the two motors is that the 427 side oiler motor is more original, but usually in order to find one, you have to have it (re) built by an engine shop. There are several mentioned all over this site, such as *Southern*. Talking big bucks, but they are nice.
The 460/514 motors are Ford factory crate motors, meaning they are remanufactured (I am guessing from motors returned due to warranty exchange/repair?) and they are the best "bang for your buck" in the engine dept. My 514 comes with the CobraJet aluminum heads, same rough dimensions as the stock heads, OUTSIDE, but inside, big (good) combustion chamber changes, stainless valves, Eagle connecting rods, ARP bolts, lots of goodies.the heads are Lighter too. From what I can discern, heads are the most important upgrade in the HP dept. The big mild motors like the 514 run on pump premium...low compression (9.5 to 1) big lungs, makes good reliable power.
My compassion goes out to you in California...my wife and I escaped there 10 years ago. Gas is the least of your problems there, depending on what part of the state you live in.
So, ..I went with the crate 514...600 horsepower (about $7200.00) without the Holley fuel injection ($2850.00) and MSD ignition/coil I am having installed at the West Coast factory. It seemed the easy way to go, but if I ever build a 351 to 400 small block 289 FIA style car, it would likely be a custom motor, maybe with dual Paxton style superchargers. So then it would get more expensive by far.
I hear that ability to get at spark plugs varies quite a bit motor to motor, and cobra make to make. They are NOT *all the same*
You can see West Coast cobras at
www.cobrakit.com
I bet others have lots of tech data to share, that I do not
