Okay only kidding about the cross breeding.Putting together a tow rig for our vintage travel trailer and our '58 Skagit 20 Offshore Express cruiser. Inherited this '74 D100 Custom 318/727 shortbed stepside from my dad.It's been in the family since '76 but sat for the past 16yrs with the occasional trip to compost site and dump runs.
In the garage now with front sheet metal removed, p/steering gear frame cracks welded ( waiting on brace from Dodge Connection ),rebuilt jy van LCA,new floor pan on passenger side, 2 small patch panels driver side floor,install jy pass.side door, prep jy L.frt fender.Picked up a CL 318/727 that turned out to be a 360/727. From a friend a free rv cam NIB w/timing set.I'm going to try a set of A body Summit headers for fit.
Here is the combo as of now and as I've mostly deal BB & Sm B chevy (so please speak slowly) I would appreciate any feed back pro or conn . I'm not married to the free cam / carb and hope to replace the cast iron 4BBL manifold at next month's swap meet. Not trying to build a tire burner but want it to be respected and sound nice.

360 great compression
cam .420 / 443 lift... 278 / 288 duration.
TQ carb. Rebuilt and road tested on our 427 Nomad.Another freebee.
A body headers
727trans original to the truck w/shift kit install in '75 by po. Still shifts strong,no slippage.130,000 miles
No clue as to wheel tire combo yet, still going through the photos here & no clue on rearend ratio.
Now lets see if I've figured the pics posting thing.

I think that combo will do exactly what you need it to. How heavy is the trailer you might want to look at air bags or an extra leaf so it rides nice and even.

Thanks rednuck
Sooo an rear axle flip is not a good idea? The trailer is 2200lbs dry and we have towed it the last 3yrs with our '01 3.0 ford ranger 4x4 sht/bd using an equalizer bar type hitch. It tows the boat no problem just no class. With that combo we are stranded on the western side of WA. state and the @#$% slow lane. The Dodge was always a nice comfortable ride but without all the creature comforts this old body now desires. I think it already has an extra leaf as it came with a matching little camper,not a cab over or shell and never squatted much,handled well.
I've tried to keep this a quick budget build to last at least a season or two while I scare up a 440 and I need the garage space to get back on de-tuning our '55 Nomad and updating steering/suspension for towing duties.

I don't have any experience with the axle flips so I can't help you much there. My only 2wd is a dually cummins 1 ton with air bags and extra springs. But if you do for the lower ride, I would probably air bag it so it's not dragging on the ground with the boat attached.

I have done the shackle flip + block removal on 4wd's with good success it definitely softens the ride out back. but if I remember correctly the 2wd's don't have blocks, you probably won't want a 4+ inch lift.

I would find some newer seats at a pick and pull place, it will help out with some of the comforts!

The engine sounds nice and the 727 can take it. The factory 4 bbl manifold was pretty good for towing and general application... Al will save some weight but probably not much power gain.

Some suggestions for towing kinda heavy. A good transmission cooler is a start. Radiator/fan/shroud in good shape. Also rear gear. 4.10's or 3.91 would be best. 3.55 maybe depending on tire size. Less than that would be a big challenge. Also a frame mounted hitch, weight distributing receiver and good trailer brakes. If you are running far and fast, especially in hot weather, I believe better rear lube helps with high temps... Mobile 1 90W-140 synthetic for example.

I almost got mad opening it up and seeing a step side getting cross dressed lol

I've towed with an axle flip Not a big deal but a small C notch is required
As far as the A body headers the passenger side will fit perfect the drivers side is a different story

Lowering that ShortBed will help it tow better

I've towed with 318, 3.23 gears and 31.5" tires. You don't need 3.91s. I'd use whatever was stock in the truck to begin with.

R.

Title reminded me of the day a guy was at a gas pump with a d series of some sort. I was in my 79 D300. Got to talking and he said he had a 427 in it. I thought he was kidding, as i dont think any true mopar guy would do such. He talked up the chebby being such an awesome engine, while the dodge truck was way better than a chebby.

He drove off and i was stunned to hear the familiar gm starter sound. my dad was with me and we both shook our heads.