Dan I guess we'll agree to disagree but from my experience (and like you I was building strokers out of 383's, 400's and 440's long before they were mainstream) the combination of the smaller bearing area and lighter bobweight (again from my expereince only) a 470 is more than enough to offset a roughly 5% displacement handicap to the 493 if those motors have the same machine work, compression, heads, cams, induction and exhaust. A bit lower piston speed means less frictional losses at any given RPM as well. Don't get me wrong, nothing at all wrong with a 493 it's just that from my builds the extra "coke can" or so of total displacement only brings it about even...again all else being equal.

I also feel confident backing that up because you can (well, I can) definately feel the difference between a comparable 2.200 journal 511 and a 493, again it's I feel it's the smaller internals. There was a reason Bill Jenkins ran 2.00" rod journals and not the 2.100"s all those years ago. And don't guys still swear a comparable 327 will walk the dog on the same spec 350 chevy? Now NASCAR runs 1.89's, less surface area/rotating friction with still sufficient strength I suppose. It's interesting, in my day job I'm working on a huge 65.5 Megawatt Hydro turbine generator and I'm working with some very clever engineers who I'm learning a lot about the criticality of bearing temperatures and pressures. The stator is roughly 30' in diameter

Lets take a 'real world' example (not an all-out race motor) of a street-strip 10.5:1 E-headed motor with an MP 557 cam, both have a 950HP and an RPM or a street dominator or an M1 (you pick) and 2" x 3 1/2" headers with a 3500 stall 10" t/A and 3.91 gears in a 67 coronet. I'd lay money down that they'ed run virtually a dead heat in the quarter, round after round. if there was a difference it would be that the 470 would peak a few 100 RPM higher, put a 4.10 in the 470 and it would be even quicker. What I've outlined here is the basic bullet-proof reliable 11.70 & high 1-teen street strip combo, I've done it with both motor combos...but with ported iron heads. Of course these days everybody seems to build 511's so I suppose the old school 470's are out of favor...but back inthe day they were the hot "stealth" ticket Heck it's easy to go 11's with just a basic E-head 440 these days.

If you asked "why would you build them the same?", I would have to ask you (respectfully) why couldn't (or for this example relating to heavy street/week-end strip use which is what most people on here build for) wouldn't you build them essentially the same? It's a 'fun' motor either one.

but going back to the original post, I wouldn't EVER feel like I had to defend running an RB and in his case...I'd just smile and say "Because it's the one I had!"