need input (johnny 5)

I got the 'Johnny 5' bit. That was cute. Let's see who else get's it.

Per the 'dump' question (that was good too ..... ), I've been a stinger guy for years, so I'll let the high mounts take this on. Seems to me thoo that Sun Valley and Sun Country make pretty heavy high mounts.

 

We have a 5307 behind a Century. You'll end up heavy on the trailer long before you find gross. I ran a 5309 behind a 630 Volvo, and that one I managed to get close to gross once or twice, while staying within axle limits, but it wasn't often (or easy.)

That wheelbase is fine, although getting around in some dealer's lots is chore in the highmount vs. a stinger because of the greater off-track.

The biggest problem with a highmount is the varying ways that states enforce the length limits. Legally, they fall under the rules for regular trailers, not auto transports. Some states give you 3 off the front and 4 off the back, others will nail you for front overhang, etc. etc. etc.

 

The tare will be between 23 and 25k, which is not bad but to do a 8 car load on them you may have some axle weight issues. As said above, you will not get close to gross but may have axle issues some times. I run a Miller 5307 and pull it with a single axle, never have a problem, usually gross at 51 or 52k, never more than 20k on my drive axle, about 10k on my steer. When I had my tractor with the cab rack I had a heavy steer axle in it, I was find if I loaded the roof car nose first, if I backed it on I would put my single drive axle over, not a problem as long as you are aware of how the weights distribute across the trailer.

I do think a 270 inch wheelbase is overkill, and as said above you will have problems in some states that have different rules for high mount car haulers than stinger steered units, or even regular tractor trailer combos, for example in my home state of Pennsylvania if you are off the National network you can not be over 65 foot bumper to bumper and no over hang, New York allows 4 foot of rear over hang but no front over hang (although that varies according to which officer inspects you). I do mostly lease turn ins from dealerships to auctions with some repo yards thrown in there for the fun of it and I would not be able to get to some of those yards with anything much longer than 230 inch wheel base, especially in the New York metropolitan areas. If you are just running terminal to terminal or auction to dealer you may be alright but if you have to do POV's (personal owned vehicles) expect to have trouble getting into some residential areas and shopping centers (which is where the public likes to meet transporters). Hammer nailed it with the off-track, if I had it to do again I would bite the bullet and get a stinger, even though it is longer than my current rig it would be easier to get around with and have less DOT issues.

One last thing on the long wheel base, parking in truck stops will be hard, even with my 160 inch, single axle day cab I hang out of parking spaces when backed in next to 53' trucks with sleeper cabs because I can't back the tail of my trailer over the curb due to the low profile. The low side rails also present problems with curbs and such, you can't track over these like you can with other types of trailers to get into tight places. After 17 years of doing this I recommend as short of wheel base as possible if you are going with a high mount trailer, although with a short wheel base it does limit what you can hang off the front of the trailer, but as said before you can't legally hang over the front in most states.

Good luck with what ever you choose.