In Fords, the E350 Class C had the 460V8 since who-knows, late 1970's probably through 1996. In the late 1990's they brought out "E-Super-Duty" which was later named E450. I believe those came out in 1997 or later. 460 was dropped and they went "modular engine" at 5.4V8 or 6.8V10. Before the 5.4V8 Ford had a 351V8 that was a good engine but very uncommon.
GM... Had 350 and 454. The common Chevy engine was 350, and they dropped 454 before Ford dropped 460. Then they brought out the 6.0V8 and a monster 8.1V8. The big engine lasted only a few years. The 6.0 doesn't sound like much over the 5.7 but it's a little tough guy. Performs close to Ford's V10.
This is just me, but...
A Ford with 460 likes to use gas but it's powerful and dependable
A Chevy 5.7 is barely adequate if coach is a true, full-on Class C
A Chevy 454 or 6.0 would be nice
A Chevy 8.1 would be very nice
Ford's 5.4V8 and 6.8V10 are very good engines. Good power, good reliability
We've had two Class C's, a 24-ft with 460 and 31-ft with V10. We miss the compact 24 and the down-and-dirty power of the 460. It's the quintessential Big Block V8 with Chevy 454, 8.1, and Chrysler 440. The V10 does a great job given the 31 is 3000-lbs heavier than the 24. I'd still like to see what the last of the 460's would do in our same coach!
Transmission-Wise, it's been a seesaw. GM and Ford had three-speed automatic for a long while and I think GM jumped into 4-speed overdrive first. Then both went to five-and six-speeds with trick functions like Tow/Haul.