Well I have a 247/255 in there now. Lift is not a concern at 549/571. I can't stop it from bucking when trying to lug it around. I can get idle down to about 800.
The smaller XS268S cam at .050 with 230 degree on the intake valves and 236 @.050 on the exhaust may or may not have the same rate of valve opening as the one you have now.
What brand and grind is the one in the motor now?
The reason I bring this up is you need to compare opening rate as well as lift when shopping for cams, same advertised duration can be way different at .050 on the same brand cams, let alone from different cam companies
I've been checking camshafts since the early 1970 from a bunch of different cam companies, the newer grind like the Extreme Energy compared to a older grind like the Mopar cams have or a older Isky or Engle grind is like comparing a 1962 Corvette to a 2010 Corvette or a 1970 Challenger 383 Magnum to a new SRT-10 Challenger
The last Isky solid roller grind 440 cam I checked, RR602 grind, 260@.050 on both valves, open the valves so slowly that it really shock me
It took probably 60 crankshaft degrees to open to .050
On your deal not wanting to keep the engine revs up above 1200 RPM in any gear to cruising your probably doing the correct thing for your desires
I'm the opposite, big cams and rev them babies up
My last street car had a Comp Cams solid roller cam that was 260@.050 on the intakes and had 266 @.050 on the the exhaust ground on 108 LSA and installed at 106 ILC, It sounded milder idling at 850 RPM in gear than it did at 1700 RPM cruising in second gear at light part throttle
It would really cackled and bark at 1200 to 2000 RPM
I'm a racer and I couldn't get any of the local street racers to play with it on the street or at the local 1/8 mile track
