In a 500" motor anything smaller than about a 242 degree @.050 hydraulic is going to sound like a broomstick if it has decent compression.

In a heavier car where you're looking for a big upper bottom midrange punch I almost always go with a tighter 108 spread...With a flat tappet I'd leave the 112's for either a lighter car, or an exhaust limited motor (too small headers where minimizing overlap could help reduce intake contamination and enhance VE) or going big in a stick (or very traction limited car) that might not hook up with fast torque rise in the middle. 112's can work very well in Hydraulic roller apps and solid F/T's that have quicker ramps but with a Juice F/T in a street car I lean hard toward a 108...There are combos where a wider spread makes sense but probalby not for this one, tough to get the big power AND the sound you want with a hydraulic F/T in a 500, not without going to bigger ramps....by comparison both a solid and a Hyd FT will have more aggressive ramps (between .05 and .200 lift) so the EFFECTIVE overlap will be more and can compensate somewhat for the wider centerline angle....hope that makes sense.

If I had to pick an off the shelf Hydraulic that will have a decent lope (not sound like a milk truck) I would pick the Comp 305 Magnum (253 @ .050 and .525 lift) but I know first hand the Comp XE 241/247 makes very good power with decent heads in a 10.5:1 440, I think that choice would still sound a little too mild in a 500 (for my taste) but I think it'll at least have a hint of chop to it....it's a good cam and the other one you list is too small in my view for your app.

For dual purpose ou want to cam a 500" motor "right" ....by that I mean it should sound mean but actually drive pretty docile around town and not require a ton of stall (though the big torque will effortly raise the flash)...it should feel ideally (my ) like riding a very powerful horse and with a light throttle you feel like you have to hold back the reins cause she just wants to get up and run every chance it gets.

I agree with Andy that a Hydraulic roller is a very good investment for a 500, the extra duration above .200 lift they give you allows you to keep the idle quality good but still gives it a bit more "lung" up top for better VE and higher RPM capacity.

I've got a 245/256 duration (112 LSA) juice roller in my 528 hemi. It idles at 800RPM and has just a little "roughness" to the idle. I'd lean towards a 240+ duration cam unless you want it to sound as mean as a school bus.

You guy's are the best! Thanks for all the input and suggestions

Streetwize, thanks a ton for the indepth explanation. After reading the posts here and a good friend of mine persuading me, I decided to go with a solid cam. It'll be my first
I always feared the need to conastantly adjust the rockers, but I have been assured with roller rockers, adjusting is not so frequent

This brings me to my final decision. I am going to try the .557 MP cam.
The specs of the Comp 305 Magnum are very similar to the .557 as well as the other favorably chosen cams (approx .5xx list, 25x duration and 110 LSA).

I'll try it out (yay BDS71Cuda) and one of three things will be the outcome. Either I'll have to drop the trans and add more stall to the converter, swap the cam for less duration/more lsa??, or it may just be what the doctor ordered

BTW, love the School bus / Milk truck comments

Thanks everyone and I will definitely keep everyone posted on the outcome

The ol' 557 is also a great stick, it'll work great!

BTW, for comparison check outh the 511" 477 RWHP build currently in Q&A.

Also for comparison This is what a 12:1 517 with a 265-ish @.050 on 108 Hydraulic roller idles like:

http://www.youtube.com/watch?v=lN9uEzqzdA0&feature=related