That's not a bad choice but a little conservative for the 4.25" arm in that motor, something around 238/242 @.050 .585/570 lift and 112-113 spread in at ~107-108 would give you close to the same intake closing but get the valve up and open a little bit earlier and help extend the powerband another 400-500RPM. 230 is a little short for a 500" motor IMHO it just limits the breathing up high when the stroker piston speed starts churning at a comparatively low RPM.

I had a 252/258 @.050 on 112 Straightline HR in my old 508 (the same motor I sold to Paul PHJ426) and it was really mellow sounding with headers....made MAD power and torque everywhere but sounded suprisingly docile at idle. That motor had headers though so with manifolds you don't want to run a lot of exhaust duration. The 'trick' to running exhaust manifolds with a stroker is you have to find ways to make the intake and exhaust tracts work 'on their own' since you're taking away any benefits the overlap draw at a proportionally lower RPM. An agressive higher lift intake, wider centers and a slower exhaust ramp to hold on to as much cylinder pressure as possible (for as long as reasonable) to push through the restrictive manifold.

My 'rule of thumb' with a street stroker is I want to put as big an intake lobe on it as I can....up to the point where it is just about to start killing torque at the low end of the rpm range/powerband...compared to a stock stroke motor that's a bit bigger than a 230 @ .050. I'm sure it works very well, but to me that's kind of a broomstick for a 505.

Too much torque down low makes it tough to hook and then you run out of steam too early....kind of like the Olds 455 or a 428FE used to.

Being a roller I'm sure they could regrind another 10-12 degrees into it....just on a slightly smaller base circle....on a stroker the 238/242 I suggested could be worth 40-50hp and 500 rpm with no appreciable loss of torque off the bottom just on extending the powerband 238 @.050 is about the smallest I would ever put in a 4.25" stroke street motor, in fact I just speced a Bullet HR for a similar combo for a customer in Austrailia.

If he doesn't mind going to a solid one of Fast68Plymouths grinds might be just the ticket but the .612 F.A.S.T. racing oriented grind I suspect will have too agressive of a ramp for normal street use....check with him well worth looking into.

Also a tight 9 1/2" converter (maybe 3200 FB stall /4200-4400 flash) would feel very good on the street and cruise nice and feel almost stock-ish tight at 65mph with highway gears behind a 505 and really allow that thing to roll-on... if you 'get it right' a 500 (with a manual VB) will accelerate about as hard from 45 mph IN HIGH GEAR as a stout 440 will kicking down to passing gear from the same 45mph roll.