Powertrain Advice

[Jmjuhl]

I know this topic has likely been beat to death but I am going to kick the dead horse one more time for good measure because the search function isnt the best.

In the planning process of frame off and trying to iron out my powertrain before I move forward with my 74. Current setup is 302, 3sp floor shift, Dana 20, 44, 9". I have researched engine swaps until I can barely see straight and wanted to get some input from the group.

Ultimate goal is reliability and drivability so I am pretty set on EFI of some sort. The purist in me is gravitating towards a crate motor 351W or stroker variant like 408 with something like the Pro Flo EFI. They just sound at home in the EB's. My hang up is the perception of bugs with aftermarket EFI systems and streetability, overheating, etc.

The other side of the coin would be a Gen 3 Mustang or F150 Coyote swap. Should check all the reliability boxes but the pure low end torque for wheeling, although still a significant improvement over stock 302. F150 motor would provide lower end range but degree of difficulty goes up a bit more as I would have to source a low mile pull out motor which has some risk.

Planned usage will be 50-60% street usage, short trips to the beach with wife and two younger boys, and occasional 70-80 mile trips to family property. Living in a large city highway usage will be guaranteed so road manners are important. Other 40% or so will be mild to average weekend wheeling (little rock crawling) and general skinny pedal fun.

90% sure I stick with a manual with OD (Ax15 or TR 4050), Plan is to build the 44 front with RCVs and a LSD/Locker, 9" rear with 35 spline and Eaton TruTrack...4.56 gears, Atlas 2, 1350 yokes and shafts. Probably overkill but want it to handle power, and not that I plan to ever sell it but thinking of resale if I do. 2.5" suspension lift, 1" body for clearance, 35 x12.50's

 

[DirtDonk]

I donÂ't think loss of low end with a Coyote is even a thing unless you go wrong with your differential gearing. My reasoning being the sheer numbers. ThereÂ's probably a flatter curve with the Windsor, but the coyote probably has a big overall number advantage even below 2500 RPM.

That said, IÂ'm a big booster of the older architecture in Broncos. I prefer Windsor family engine almost every time. Unless youÂ're looking for the cool factor, in which case the new stuff wins hands-down. And thereÂ's no rule saying you canÂ't get good power with mildly modified factory EFI parts on your 351-408-ish engine.
ItÂ's just an easier fit in a bronco. If you donÂ't mind a little more work and a lot more money though, then either way is still an option.

While that doesnÂ't exactly help you make a decision, it might still help. My vote is for the Windsor.
Both can easily over-power an Early Bronco. Sounds like you want to have fun with it like a hot rod occasionally, but donÂ't forget the safety aspect with the family. These things somewhat decent handling, but theyÂ're not sports cars. Maybe a 375hp 408 isnÂ't really worse than a 450hp Coyote after all.

Paul

 

[sanndmann3]

I vote for 408 like Paul said. Consider Explorer E.D.I.S. fuel injection for reliability. I did 351W years ago and wish I went bigger. The 351 rocks but I imagine the 408 rocks more...

 

[jckkys]

Where is this purist you claimed is in you? It seems you're building an EB with purely non EB parts.

 

[DirtDonk]

Probably overkill but want it to handle power, and not that I plan to ever sell it but thinking of resale if I do. 2.5" suspension lift, 1" body for clearance, 35 x12.50's

Just as a side observation, of the stuff you mentioned very little of it will enhance its resale value. Almost none of the underneath stuff, or suspension, or wheels and tires will enhance the resale value (at least in the current market) as much as new paint will. And likely the Coyote motor swap will add more value than a Windsor swap, simply because even someone who doesn't know anything about Broncos would know that was a lot of work and expense to put in.

That all may change in the near future, as buyers tastes change, but for now nice new paint sells more than off-road goodies and suspension mods and wheels and tires do.
That's not true 100% of the time of course, and I may have missed some new trends. But it's currently still the more common theme.

Paul

 

[Jmjuhl]

Just as a side observation, of the stuff you mentioned very little of it will enhance its resale value. Almost none of the underneath stuff, or suspension, or wheels and tires will enhance the resale value (at least in the current market) as much as new paint will. And likely the Coyote motor swap will add more value than a Windsor swap, simply because even someone who doesn't know anything about Broncos would know that was a lot of work and expense to put in.

Paul

The resale comment was more aimed at the fact that the entire documented build was quality components along with paint etc, versus just pouring power to a stockish driveline hoping for the best. Reality is that will be my kids concern when they inherit it.

 

[Jmjuhl]

I vote for 408 like Paul said. Consider Explorer E.D.I.S. fuel injection for reliability. I did 351W years ago and wish I went bigger. The 351 rocks but I imagine the 408 rocks more...

I hadn't considered the Explorer or Mustang FI route for some reason...that seems to be a decent solution...I need to research that some more as that might get me over the hump on the 351W/408 route.

 

[73azbronco]

Crate 351 or stroker, proflo induction, 4r70 or 6r80.

I would not go mustang or explorer efi, except for the serp. Wires from 10-30 years ago just don't do well when moved around.

 

[DirtDonk]

The resale comment was more aimed at the fact that the entire documented build was quality components along with paint etc, versus just pouring power to a stockish driveline hoping for the best. Reality is that will be my kids concern when they inherit it.

Gotcha. No problem with building it right and the way you want it.
Especially for yourself and your family!

 

[Rustytruck]

reliability comes from stock form. good enough to last 50 years with very little maintenance. nothing you do will add reliability just complicate things and drive up costs.
now drive ability is a very big grey area. your taking a piece of farm equipment and trying to fit it into a new 2021 Bronco. your better off and cheaper with a new bronco if they ever figure out where to get computer chips.

 

[73azbronco]

Rusty, my point is,, using original wires is a bad idea. They crack. They short and ground. The A9L can only be soldered so many times. Now, the sensors if all new, a new wire harness, and a new a9l and you have a solid performer. The problem is finding a reasonable a9l replacement which I don't know if those exist. Otherwise, for reliability, you need a new system like a proflow.

 

[Rustytruck]

Rusty, my point is,, using original wires is a bad idea. They crack. They short and ground. The A9L can only be soldered so many times. Now, the sensors if all new, a new wire harness, and a new a9l and you have a solid performer. The problem is finding a reasonable a9l replacement which I don't know if those exist. Otherwise, for reliability, you need a new system like a proflow.

I agree with you and your thoughts as I would do the same as you suggest. But it isnt going to make the Bronco more reliable by adding more sensitive failure points than a stock ignition and carb car. every complicated twist we add from the brakes to a soft top doesnt make the truck more reliable and easy to maintain it just makes us more in tune to what we have as we need to fix it. The stock Bronco is easy but take it into a modern day shop they don't know where to plug the computer in and have little to no knowledge about rebuilding a carb. any mechanic trying to repair my Bronco would go nuts from the Chevy disc conversion to the ford hydro boost and quadrajet carb.