Well, here's the BASICS for best driveability for street, occasional track and remaining at least partially true to the "spirit" of a Cobra. This is NOT going to be a "show" car.
FE (of course we start there), unless it's an FIA style, then we might go 351W. Carb: While I prefer the center pivot single four for the track, I want a vacuum secondary for the street. Street is the most miles, so default to vacuum secondary.
Not to big, runs LEAN, we will build the motor to deal with that.
Stroke it! 427 with a 428 crank will do the job, or something equal. Or a 428 with a mild stroke or left stock. Heck even a well built 390 would work well here! What we want here is TORQUE for the street. Pistons: The standard FE's series motor have the pistons to low far below the deck to address "quench". Bring the pistons up to .005 below deck. The heads are closed chamber style or you won't gain any quench from moving the pistons up. Alloy heads, go for about 10 maybe 10.5 compression ratio. With quench, we MIGHT be able to go 11 to 1, alloy heads. Iron heads 9.5 to 10 MAX. This assumes pump gas, 92 octane. FORGED pistons, by the way.
Camshaft profile. Couple of things here to watch for. GOT to have a "lumpy" idle, sounds mean sitting a stop light. Hydraulic roller, OK (MIGHT NOT provide the lumpy idle)! Solid roller with pressure feed, OK. Flat tappet, OK. Don't need high rpm, 6000 or so will be enough. Lumpy idle cam means your likely over a 6000 rpm limit anyway, thats OK. 6200-6400 will be fine for the track. Cam profile needs to work well in the CRUISING rpm range. With our 5 speed OD trans (still need exacting specs for the trans) engine rpm should come in around 2000 at cruise rpm and the cam profile should work well in that range.
Trans: 5 speed with gear ratio's equal to a top loader on the bottom four. OD will be point 8 (NOT .6). Forward facing gear shift of course. Rear gear ratio, IRS of course, should fall around the typical Jaguar setup of 3:31.
Timing: This is a CRITICAL area often over looked. We want this part DIALED IN to work well with our quench, compression ratio, carb setup and street driveability. Were going to need LOTS of advance for BASE timing. 16 to 18 minimum, 20 is likely. Our "lumpy" cam will demand it. Set timing to "just below" the starter having a hard time cranking the engine over. Again, the quench is a big factor here, we can run 38 total, maybe a bit more with our quench. We want as much timing as possible! VACUUM advance unit is a must. About 10 degrees advance from that, I prefer direct intake vacuum for the signal. That gives us better idle conditions and a LOT less tendency to "diesel" on shut down. At high mph cruise rpm, with mechanical and vacuum advance were looking at about 45 degrees total, maybe 50 or so. We likely WON'T get full mechanical advance at reasonable cruise rpm, so were going to rely on the vacuum signal to get it up.
While I LOVE the Goodyear bill boards, their not rugged enough for long distance cruising. Consider a set of radials (15" or 16", 15 preferred). I'm not crazy about street drag tires for a long distance cruiser.
A little bigger gas tank, 20 gallon minimum for decent range between stops.
Soft top, side windows, heater/defroster. Another set of wheels with track tires mounted and ready to swap on is a real plus! Get some decent looking wheels while your at, not some Chip Foose or whatever chrome bling thing! Shesssh, that is my number 1 pet peeve. Cup holders, coffee for cruising. I have some ideas here, but thats a huge variable how to get it done.
Less chrome, more paint! Keep the shiny bits to a minimum and DON'T start polishing stuff. You will spend WAY to much time worrying about the shine going away! Remember, it's a CRUISER for long trips, a DRIVER car, not a show car.
Oh, and single roll bar, chrome is OK there. Quick jacks look GOOD, but the full bumpers front and rear might be more practical, tough call. No sidepipe covers, learn to step away from the sidepipes getting in or out. Be proud of the "snake bite" burn scars on your lower legs until you figure it out.
