Build: 92-97 F-250 Crew Cab 4X4 460 (possible stroker) Manual trans


1st: ZF-6 swap to a 460, based on the 7.3PS bellhousing pattern. Has anyone done this or know of swap kits available? I've researched without any findings.


2nd: Overdrive units or better ideas/suggestions? Looking to get the best possible MPG on the highway with my build. Doubt if I ever tow over 6,000 pounds, if that needs to be considered. I hope to achieve 20+ mpg unloaded!


3rd: 460 engines/blocks I should avoid, bad castings etc.? There is a 71' 429 4v complete available that I could buy. However, I want to run a factory serp belt set-up (A/C) from 92-97's. I hope to use aftermarket TBI, like the Holley system that's going to be released soon. It's the same as one of their other companies system on the market? MSD will handle all my ignition needs.

Diesel is out of the question for me folks, the cost of upkeep and future repairs. As a "disabled/retired" locomotive engineer, I'm done with the fumes too! Plus, I want the luxury and availability ($$$ savings!) off of the shelf parts. Thanks in advance for GOOD help/advice & suggestions.

 

https://holley.com/products/fuel_sys...4bbl_tbi_kits/


http://www.msdperformance.com/AtomicEFI/home.aspx

 

Welcome to FTE, D'rail. Cool avatar.

385s aren't my thing but I'm trying to learn.

I don't think you can do the swap on the tranny without some sort of custom adapter if available at all & 20 mpg is a pretty long stretch.

Not sure that the 71 is going to be any great score unless you're willing to put a lot of machine work into it after such a long time. They usually need it by now. All 385s are pretty much reliable as a brick through a plate glass window. A newer engine with just rings, bearings & gasket freshening might be better choice financially.

Perhaps others will chime in. Welcome again to FTE.

 

I don't think the difference in OD ratios would make the ZF6 a great financial choice, if fuel mileage is all you are after. I also think that 20+ mpg unloaded out of a 460 is unrealistic. Based on my research, a 460 that gets 15 mpg on the highway is doing really well. Lowering the engine operating rpm on the highway with a GVOD or similar may help, but I don't think it will get you anywhere near your 20 mpg goal. With what you will spend on aftermarket EFI, and an auxiliary OD unit, you can buy a lot of extra gas.

 

Waste of time attempting a ZF6 swap

ZF6 has a .72 OD
ZF5 has a .76 OD

 

Thank you Sir, that's the ONLY curved RR bridge east of the Miss. River, well documented and very historical.


ZF6-460 swap kit would be exactly what I'm after, if available. I've found nothing. Now, if I could find a kit to swap from the modular gas engines (share the same pattern with the 6.0PS as I'm told?), this might be a much easier route???


Honestly, I'd love to use the old 71' Lincoln 429 as the bottom end has forged factory internals. Long term, no emission BS (EGR's etc.) to deal with and with fuel injection ($1,000) available... It would allow me to really dial it in, intake manifold and cam etc. Double edge sword..

 

It sounds like youre bent on having a ZF6 as opposed to a ZF5, which as others have said will give negligible mileage gains, the extra low gear and ever so slightly higher OD gear were changed from the ZF5 mostly for advertising and being able to say that you had 6 speeds instead of 5. Also, if youre looking for mileage, its a logistically horrible to start with such a large disp. engine and truck. Unless youve already bought the truck, I would start with maybe even an F150 if the absolute most you will be towing is 6k lbs. A 351 should give you 15 mpg if youre light on the go pedal. If you do need the crew cab of the F250, then be prepared for 10 mpg from the 460, 15 is possible with a reg cab 2wd truck but with a 4x4 crew cab, 15 is extremely difficult to obtain. Sorry to be another bearer of bad news, but a 460 build wont give you what you want

 

Agreed, the ZF6 (I believe, .04 final OD ratio) a slight improvement. But, I'm thinking about other benefits also, the pump an aux cooler etc.. I couldn't agree more, a bone stock 97' 460 getting 15mpg is working very well. Now, that same truck tuned and the OD unit an other improvements (electric fans etc.).. I don't think 20mpg is unachievable.
Consider trips of 1500-4000 miles over the 5-10 years(This truck may even go to the grave with me!), that's huge! You think the price of gas will ever rise again?
Now that gear vendors OD, it has 19 months/17,000 miles of use on it. My best friend (basically my brother), he shelled out the $2xxx for it new, I can ****** it up for $750 or less. That Holley TBI system is $1050.. I think it would easily pay for itself within a 2 period. No smog pumps, no EGR valves getting loaded up with carbon, plus other MPG robbing codes & failures. Now tweak that Holley TBI, AF ratios timing etc....

 

Again, not to discourage, just to inform, but those 15 mpg 460s are the ones that have already had electric fans installed, been tuned to the enth degree, driven like old lady trucks, and are light trucks in the first place, not crew cabs. The only trucks, on these forums at least, that have had a recorded and confirmed 20+ mpgs are mainly 300s with the occasional 302. The new EFI system will also take time to adapt and tune

 

Strictly for maybe .25 mpg improvement, that's a very legit statement! There is other benefits that I taking into consideration too (the cooler). Wouldn't the ZF6 basically be bulletproof in my application?

 

The ZF6 is available to me. My experiences with the trans really made me appreciate it, looking long term in my application, I don't see many failures long term.
We trailered a Fairlane 2K miles with 7.3 ZF6, thru mountains and so on. The trans just works very well from my experience! If I'm not aware of something here with it, please share!

 

There's nothing wrong with it except for the fact that it's much more work than installing a ZF5 for no gain besides bragging rights, but go ahead if you wish

 

Do it. I'd like to see a manual 6 on a 385. Put a GV on it too. This is an enthusiast's forum & you're allowed as an adult at this point in life to do what ever the hell feels good & your wallet & time allow.

We like pictures.

 

Completely agree, a 6 speed 460 does have a nice ring to it, just a bit too much work for the average fabricator

 

Ha! Bragging rights, really?... Help me with that one, please. I don't see anything below my posts about this truck/car I own with this mod or that mod blah blah blah.


I've owned the new stuff, I've also spent many hours/days/months waiting for Ford to fix problems with the new stuff. Stuff that NEVER was corrected. I got tired of it so, I had this crazy idea building the truck I want with goals and purpose in mind. If you were in my shoes? I can go over to a friend's house, hand him $150 or whatever, and he'll help me load the ZF6 in the back of my truck. It's that easy! I don't have to go buy a parts truck, I don't have to lay in the dang mud on my back at the salvage yard to yank one out of a junk truck.