Lots of good discussion here.
Couple things to add.
1. Either you add overdrive somehow way shape or form, or you can’t maximize towing power AND high speed cruising. If ya could, overdrive transmissions would have never been invented.
2. You’re being optimistic on tire height vs rpm’s. With the 465 it’ll be direct and rpms more true and closer to theoretical than say a th400 with no lockup. But th3 tires you’re using will have an effective diameter of maybe 31” when new and less with tire wear. You’ll be more accurate using a tire height about 1” less diameter than theoretical.
3. Agree 4.56 especially with the 465 and big block power/low revving high inertia engine is too low. Like someone said, first gear will be like 6million:1. Lol. 4.10s and no OD will still be miserable for bobtail on the highway. And with the short tires 3.73 is as deep as I’d even consider if I wanted to bomb down the road at 75mph for any length of time.
Back to #1. Do you want it to be the best at towing and prohibitive to drive fast for hours or do you want mediocre towing and the ability to cruise at 75?
Whatever you do will be a compromise without OD.
Are you building an engine or is it a stock smogger? Gotta put the money somewhere… you can sacrifice deep gearing for horsepower and maintain highway manners, or put some real quiet mufflers on the smogger, gear it down, get some Bose noise canceling headphones for 80mph road trips and run’er until she tosses a rod!
IMO I can’t see restoring an old truck, putting a pile of time and $ into it and then using it as a work truck. Especially if you have a big bombed newer diesel parked right next to it.
I love the ole 454/400/4.10 truck and it goes our 6klb boat just as fast as you wanna go. But there’s a zero % chance I’d hook it up for a 3 or 4 hour tow, having a 2016 Ram diesel parked right next to it.
First part is objective. Last part is solely opinion.
It sounds like an awesome build no matter where you end up for gearing and transmission.
