That's quite a collection. Do you want a solid lifter cam or a hydraulic? What is the engine going in and what do you want the car to do? stock cruiser? hot street? drag race? Some of those cams are quite racy for a 273 and will need big converters if you are running an automatic and some pretty steep gears. Those cams also will need some pretty slick cylinder heads and of course headers and free flowing exhaust to work. What kind of intake have you got? No sense putting a cam in that develops HP @5-7000 if the intake works from idle to 5000 rpm. Lots of questions to be answered.
The Isky E-4 is a solid lifter cam and the specs are pretty close to a stock HP 273 cam. It has a very slight rough idle. It doesn't have enough duration to have much chop or lope. It will work fine with a stock converter and 3:23 or lower numerical gears. The Edelbrock cam is a close copy of the Isky cam only it is a hydraulic. The Melling cam is similar to the Isky and the Edelbrock. It's a hydraulic also and is good for torque and RV use in 318/360's. I like the split lift and duration for 273's especially if you are using stock manifolds. The exhaust valves are opened further and longer to make up for the restriction.
I couldn't find much on the Crane Fireball. I know they are making cams again but don't know whether they've re-introduced the Fireball. Those cams were a $49.95 cheapie back in the 70's and had a bit of duration for a bit of chop at idle. The smaller the motor the more the chop. They were cheap and not big performers. The Comp is a solid cam designed for racing. 255* duration @ .050 will get you around 300 advertised and would be too much for a small cube motor unless you're building a race motor. .540 lift is another reason. The MP cam is in the same league with the Comp. A lot of duration and lift above .525 is awfully big for a small cube motor. Which one would I choose? It depends what you are doing with the motor. toolman
