Repowering your Bronco is a personal choice. It definitely tops the "COOL" factor in Bronco mods. As with anything, it has pros and cons, which I will list here.
PROS:
- As mentioned, there is nothing better than telling someone you have a big block :-).
- Gas mileage in most cases where you started with a smaller (possibly under powered) carbed motor, will not decrease.
- Obviously power will increase, dramatically over stock 351M engines, most 302's, and I-6 engines.
CONS:
- May not be emission legal in your state
- Access to spark plugs and other items may be limited compared to non-big blocks.
- Extra weight may cause nose to droop slightly, and the dynamics of extra weight in front will be magnified even further than the visual static changes caused by weight.
- Cooling system may need to be upgraded.
- May be more expensive than upgrading your current motor.
So lets get to it. Here is a list of parts and things to consider for:
CONVERSION ON 78-79 BRONCO'S
By Norm Tischer/Anthony Johnson
By Norm Tischer/Anthony Johnson
- If the Bronco has no lift, you will need a rear sump oil pan to ensure it will clear the front differential. If you have 6" lift, front sump pan will be no problem. 4" lift is OK for street use only. Ford Motorsports makes an oil pan for the FOX bodied cars that makes a nice Bronco pan. Remember the oil pump pickup has to match the pan so it can be involved if not researched correctly!
- You will need a set of L&L motor mounts (lifetime warranty). The frame stand-offs sometimes require a little "working" to get installed, but you only have to do this once.
- The exhaust is a tight squeeze on the passenger side with car
type manifold. If you use the L&L mounts the early model car
manifolds will not fit! The later models...(after 74) will work but
are very close to the frame.
The solution is a set of manifolds from a 460 powered van...these fit well and clear everything. The 460 pickup stuff will also work as long as the donor vehicle is pre 80. L&L headers that are of the fender well design fit OK, but your limited in tire to header clearance to nothing bigger than 32's! L&L does also make an in-chassis header. Hooker also makes an in-chassis header for the swap...but it must be used with their frame pads/mounts ect....about $650 for the kit!
If a person wants fender well headers the best by far are the Headman Hustler series for this swap....They aren't cheap but fit perfectly with no interference anywhere! Also Stans headers makes an in-chassis TRI Y design header. They seem well made and fit well but are not suited to a performance engine that needs to breath really well. They have a small primary pipe diameter and a small collector also.
- Cooling system may need to be upgraded, depending on the climate and stock radiator. Fan shroud is different, but can be swapped over from M-blocks. There are at least 4 different radiators for 78-79, F series trucks.
-
- 3 core, non AC
- 3 core AC (wider than non-AC, uses different radiator support also)
- 4 core, AC (not factory, same dimensions as 3 core AC)
- Factory big block radiator, much deeper/taller than any of the other 3, very expensive.
-
- PS pump may hit power steering gearbox. The factory M bracket
will not work. You can use a early 73 or earlier full-size car pump
and bracket! All that's required here is the hose be redone to
match the pump! But if this route is chosen you will need the
pulley for the water pump and alternator and air (if so equipped)
because they use a wider belt than the 75 and latter stuff!
Actually all the brackets and pulleys from this vintage car will
bolt right in!
The other (and better) option is to use the early car brackets for the alternator and air conditioning and getting a Saginaw pump and bracket from a van. This bolts on with room to spare and works with the rest of the car stuff perfectly, plus you get a better pump in the process! But if you do this....you will need to get the van water pump and crank pulleys because of the belt width problem.
- Manual transmission trucks need different flywheel. Can use man transmission flywheel from a 390 FE block, but engine must be internally balanced.
- All 78-79 Broncos have transmissions with big block bell housings, making transmission bolt up not a problem.
CONVERSION OF 80-83 BRONCO'S (equipped with
302)
By Shane Vazquez
By Shane Vazquez
- It basically was a straight bolt up with no customizing or fabrication, except 2" body lift.
- Rear sump pan will be needed. If your engine came from a van then the hard parts done, if not a $189 one is available from Motorsports.
- Advance Adapter motor mounts can be had for $89 brand new from Central 4Wheel Drive, (they are in Sacramento, CA). They recommend a 2" body lift for 80's and up Broncos.
- Also an oil filter relocation kit with a 90 degree oil filter adapter (TRD-1413 and TRD 1113 from Summit Racing $39.95 and $16.95).
- If you plan on working the motor I'd go headers, PAW has Headman headers for $119.95 that are swap specific for 460's into an 80's Bronco (part # HED 89340) their # is (818)678-3000.
- A custom dual exhaust made from Meineki or other exhaust place.
- Other parts will come from the Van like kick down rod, etc. Accessories can use the Lincoln bracket set that places the power steering up top and the AC down below (reverse of Fords).
- Will need Big block bell housing C-6 if you are starting with an I-6, 302, or 351W.
EFI 460/E4OD CONVERSION
by Steve Dunham
by Steve Dunham
- I put a 1994 EFI 460 and the E4OD transmission it came with in my 89 Bronco. The Bronco came with an EFI 302 with AOD transmission and BW 13-56 T-case. The motor was supposed to go into a 1994 F-350 but the chassis was pulled off the assembly line for a QA inspection. Since the engine and transmission were already together, and the next truck on the assembly line wasn't an F-350, they dropped the engine/transmission onto a pallet, shipped it to Leanard Vasholtz of Pikes Peak Hillclimb fame (he races Bronco's up Pikes Peak every July 4) and I bought it from him for $4k. I used my original BW 13-56 t-case because it was the t-case they were using behind that combo in 1994, and it was a bolt on. Never had a problem with it and it has been beat to death offroad, towing, etc...
- Your best bet is to either find a complete donor vehicle from
which to take all the parts out of, or check into your local FORD
dealer and see if they have the EFI 460's for sale as a crate
motor. I had to buy the ECM (460 computer), chassis wiring harness
from a 1994 F-350 and splice it to the existing 1989 harness to get
everything to work properly. The engine comes with a harness
on it which includes all the wiring for the engine sensors. It
connects to a weather tight plug that then connects the engine
harness to the ECM. It's kind of modular. Same goes for the E4OD.
It has a harness which is for the transmission and t-case sensors
and it connects to a plug that then connects the transmission to
the ECM. These can be seen if you look under the hood near the
black plastic fuse box that sits on the wheel well on the drivers
side.
To make everything easier, I also bought the FORD EFI manual, the HELM wiring Schematics for both the 1994 and 1989 model year light trucks, and the HELM service manuals for the 1994 Light Trucks. The wiring schematics have all the circuit ID's and color codes for both model years, and most of them match exactly. All I did was splice the 1994 underhood harness to the 1989 harness where it meets the firewall. It's a lot of work, believe me. Took me 2 days to drop in the motor and transmission and 7 weekends to wire it all...!
- I used L&L motor mounts, custom fabricated the shift
linkage for the E4OD because it is a cable operated shifter and my
89's was a bell crank style.
I had to fabricate a custom t-case mount support and cross member, and mounted the transmission to it also. I had to buy a 4 core Big Block radiator which was a bolt in, and added 2, B&M Transmission Coolers. I had to buy a remote oil filter kit from Transdapt because the stock filter hits the frame cross-member.
- The 460 air cleaner mounts in the same exact location as a stock 91 would. I ended up buying a K&N Filtercharger kit and it mounts in the same place also. If you find that getting all the parts is too hard, you might seriously consider a late model 460, build it mildly and then run the Holley EFI system on it to gain the EFI advantages. IMHO, carbs went the way of the Dinosaur. I'll never own another carb'd truck again. I use mine more offroad than 90% of the 4WD's out there and EFI is the way to go hands down, end of story, period...
- Keep in mind, the stock FORD EFI system on the 460 is Speed Density and it won't run on anything but a stock 460. You can get away with a K&N Filter, plugs, headers and plug wires, but just about any other mod to the engine i.e.: cam, heads, intake, etc. would cause the air flow into the engine to be out of the calculated ranges burnt into their PROM of the ECM, so it would attempt to run at the end of this scale and that's it... It might work, it might not...
- If the system were the Mass Air type, typically found on Mustangs and the newer trucks, the engine can be modified and the ECM can handle it... If you are looking to run a cam, or anything other than pretty much box stock, go the Holley EFI route... It works, is simple to install compared to a FORD EFI system swap, and offers all the benefits of EFI without nearly the cost and aggravation...
James Oxley
Norm Tischer
Anthony Johnson
Shane Vazquez
Steve Dunham