So you condone illegal behavior.

 

I'm confused about how we got here from there. But gonna try to get back there so here we go. A 600 will be fine for towing below 5000 rpm and actually will make more tq on a chassis dyno below 4000 and we can all agree tq tows. As for manifolds your stocker should be fine an edelbrock performer would do a little better but not much and stealth is damn impressive starting at 2000 and up but does make good tq from idle to 2000. My shop has an FSuperDuty with a 21 foot jerr dan rollback bed on it it has a 472 with a stealth intake and 650 holley carb and lunati voodoo cam it will hall a loaded PennDot crewcab dually diesel up a 20% grade here near home at 65mph no problem but it also has 4.88 rears and turns 3600 in fourth gear at 55. Now my shop builds engines and little else for many years. I've built 100s of 460s and most need no more than a 600 but many customers swear better seat of the pants feel with others. So moral of the story is go with what you think and since you asked about the stealth and a 600 I would say you'll be ok truth is I use the stealth on just about everything the 460 seemed to respond better to it than anything else here on our in house engine dyno as well as our in house chassis dyno. Just my 2 cents take it at face value. And just to clarify didn't break any laws with the superduty its gvw is 14600 and Pa exempts emissions at 9000.