Some notes working backward
Abody bomber
268H is a safe grind, good torque but not great torque especially with a lower compression motor
look when it was designed and what gas was available
The Summit is better than buying exactly the same thing from Edelbrock, Elgin is even less expensive
an even older design than the 268 H I'd do a regrind first Like the stock cam it has really long seat timing for the amount of lift or duration at 200 Needed compression back in the day and that has not changed.
Agree with crackeback – but I do not buy cams for the sound
and the 218 was a strawman till real data shows up- just for discussion- I can even agree with Rumble about that
72Dart r has a good point use as much lift as you can but no more- and put it in correctly as advance or retard changes valve clearances
what is a small cam? Short at .200 IMHO we can use limited lift by rolling the nose over while still have the valve open a bunch where it counts where the piston is really moving
Duration is simple more duration moves up the torque curve- how much low end do you want to live without?
Excellent post rumblefish360
68CoronetRt Purpleshafts are better than most out there but they are pricy and lobes are dated
one reason is that there are better springs today- and better heads if you use head flow to help spec a cam The stock 340 cam has VERY LONG RAMPS and as you say not much lift
any idea what your cranking compression is--- stock heads, thick gaskets now? Any idea what your compression really is?
thanks for the tip about Competition components- not in my database
I'll post some in the range you are looking at later today but IMHO you are not ready to make a choice
a Note on CRANE
nm9sheham
The reason that the crane 268 is milder is that it is! Crane measures duration .004 off the basecircle whereas Comp measures at .006 so a 268 Comp is BIGGER than a 268 Crane
and Engle and Isky measure at .008 (or more in IskyMegacams) and MOPAR (which is completely different)
They are not aggressive ramps even for the Chevy lifters they were designed for
What they are is that they are SMOOTH for the time they were designed- Harvey Crane was ahead of the game as to jerk etc (at least as far as advertising it) and was in fact less hard on the valve train than Clay Smith, Howard and some others we could mention- Isky made (and still sells the same thing) cams that were easy on the valvetrain by stretching out the duration (just like the factory did)
That's why Isky Megacams rev well and are reasonably stable when over revved
so you gear low or a more modern grind will eat you off the corner- and change your springs