Explorer EFI and 4R70W to 68 302 Questions

[JKH67302]

I've read Explorer build posts for the past couple of months and have a pretty good handle on what to expect while doing an Explorer Swap. I recently ran into a deal for 1998 Mountaineer from friend. Got a great deal but it's a high mileage truck (255k), runs good though.I drove it around for a few days and its pretty impressive how well it runs and shifts for 255k. I'm in the process of pulling everything from the rig now and at a cross roads with the motor. My unfortunate or fortunate situation (depends on how you look at it) has me with a relatively fresh 1968 302 in my Bronco. I am not super wild about dumping more money into a new motor just yet, but I really want EFI and the OD in the 4r70w.

After all of my build post reading and other questions I am still not totally sure about whether or not I can run the Explorer EFI on my old motor or how it works after its done. If I'm correct, I can run the Explorer EFI and EDIS on my old motor with a rebalance of the existing Explorer dampener to 28 oz., replacing the cam sync gear to a cast one and finally having Gary program the computer for the old firing order. Am I correct that I can do this or am I missing something? Could those of you who have done this swap chime in on success or lack there of? Also, if anyone else has done this swap and has a build thread please point me too it.

I am sure I will have more questions as this swap evolves, so thank you in advance for the help.

 

[pcf_mark]

Yes you can bolt the EFI bits plus a few changes (like the balancer and cam sync) you mentioned) if you get someone (EFI Guy) to update your wiring and ECM. Some people use the Mustang distributor but EDIS is really awesome. You did leave out your fuel side - you need a fuel pump, lines, connectors and return into your tank.

For the trans you will also need a different flex plate I believe to use the Explorer torque converter (my memory is not clear on that) but make sure you grab the trans, engine plate, driveshafts (the Explorer front shaft can be shortened). Are you using the D20 or NP205? This impacts your trans mount and driveshafts.

I have done EFI and 4R70W. After disk brakes EFI is the best.

 

[JKH67302]

Thanks PCF. Im hoping EFI and EDIS beats out power steering, as I have no idea how I went 15 years without that! I almost feel stupid for not doing that sooner! I was spoiled and had a major brake issue a LONG time ago and went the disk brakes route so it's a long distant memory on how bad the drums were.

I left out that fuel systems stuff: I figured I would figure it out down the road a bit. I was going to grab the explorer pump and sender incase I went the Aero Tanks route and have one built for me. Or, I'll pick up a tank from one of the vendors. I'm not sold on an external pump right now, but Its still a short term option if needed.

I was fuzzy on the flex plate compatibility as well. I was hoping the C4 plate would work, but I was not overly optimistic about that. Does anyone know if a 28 oz. Flexplate is readily available for the 4R70?

As for the transfercase: I'm keeping my Dana 20 and I'll get the AA adapter for that.

Another question: I read about getting a spare PCM and flash, do any other PCMs from any other vehicles work or do I need one from a 98 explorer? If the lader is the case, would a 4.0 PCM work or does it need to be 5.0?

The power steering discussion earlier also made me thing about another question, how well does the explorer pump work with the 4x4x2 box and 33s? Should I stay with my Saginaw and get the mounts and a pulley from a WH?



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[nvrstuk]

You will need to have the flex plate balanced to match the harmonic balancer on the 5.0 Exploder motor or just purchase a new one with the correct weight.

 

[JKH67302]

You will need to have the flex plate balanced to match the harmonic balancer on the 5.0 Exploder motor or just purchase a new one with the correct weight.

I'm actually keeping the 28 oz motor balance since I'm keeping my old motor. I am going to rebalance the explorer balancer to 28. I did not know if they sold those flexplate in 28, but sounds like maybe they do from your post?

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[904Bronco]

I will go out on a limb here and say that you need to use a V8 Explorer ECU only... If memory serves me correctly, Garry, EFI Guy, Flashes them to the last update from Ford and then deletes items that are not being used.

I have always tried to use the correct year range for ECU's based on the donor. 96 (kind of a cross over year), 97-98 (has fuel return), 99-01(no fuel return line)

EFI Guy would be the one to ask for the definitive answer...

 

[Broncobowsher]

The correct early balance flexplate that works with the 4R70W is an off the shelf part. '84 crown vic with 351 and AOD is one example.

 

[JKH67302]

I will go out on a limb here and say that you need to use a V8 Explorer ECU only... If memory serves me correctly, Garry, EFI Guy, Flashes them to the last update from Ford and then deletes items that are not being used.



I have always tried to use the correct year range for ECU's based on the donor. 96 (kind of a cross over year), 97-98 (has fuel return), 99-01(no fuel return line)



EFI Guy would be the one to ask for the definitive answer...

I figured as much. I have a message into Gary about other stuff. I'll confirm it with him.

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[JKH67302]

The correct early balance flexplate that works with the 4R70W is an off the shelf part. '84 crown vic with 351 and AOD is one example.

I spaced that the 4R70 is a close relative to the AOD...I appreciate the help.

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[Broncobowsher]

Correct, the AOD flexplate is perfect.

But be careful NOT to get the E4OD or C6 flexplate. Everything is exactly the same except the offset is wrong. It will bottom out the convertor and preload the thrust bearing on the crank.

 

[pcf_mark]

If going Ford controller it has to match the year of the transmission. Ford used two different shift quadrants on 4R70W and the ECM needs the right signals for determining PRNDL. I would start with EFI guy and the AA adapter. That locks in your t-case. I used an NP205 so that part of my experience is not going to help you.

Engine - you have the flexplate and balancer info. Since it was a C4 you do not need to remove the pilot bushing and your starter and engine plate are good.

Shifter - your C$ column and linkage will work with some minor modifications. I had to shorten the shift rod (cut & re-weld) then I also had to modify the arm on the transmission to clear my front driveshaft by rotating it around and trimming the end.

Cooler - I had to make new lines the C4 ones did not fit. You may be able to make them work with some stretching but the ends will not work without an adapter or new lines. I made new lines from metric brakes lines so they fit the trans then put an adapter fitting at the radiator cooler.

T-case - if you use the D20 and AA adapter you need to do some modifications. I did not want to take the trans apart so I went NP205. I think it moves the t-case back so your shifter is going to need a modification.

Driveshafts - with the D20/AA adapter I think it still moves the t-case back so you are going to need to at them. The Explorer front shaft is a good choice to use for replacing the front shaft! The rear is going to get shorter that is easier.

 

[JKH67302]

While finally getting the motor and transmission out of the donor this week I realized there might be an issue with the explorer front dress on my old motor. I also read the tech article about the explorer front dress swap.

As luck would have it, my motor has what is described by the authors as the "rare" smaller bolt holes (3/8") in the faces of my heads and not the 7/16" that are found on most sbf heads. Has anyone else navigated this? I cannot imagine smaller bolts are a great idea for these brackets.

With this issue in mind, could I rebuild the GT40p heads instead? I know all the exhaust manifold issues, but I seem to remember reading somewhere about issues with the spring rates with a flat tappet cam. Thoughts?

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[904Bronco]

Can you drill out 3/8" holes in the heads and retread to 7/16" Just throwing this out... Do not know if head casting will allow this.

 

[nvrstuk]

Correct, the AOD flexplate is perfect.

But be careful NOT to get the E4OD or C6 flexplate. Everything is exactly the same except the offset is wrong. It will bottom out the convertor and preload the thrust bearing on the crank.

There IS an AOD flexplate that will bottom out...ask me how I know. The AOD flex plate that bottoms out does so by .060" on a 4r70w.

My build thread on the web site that is no more documents the part # from Summit. I have it buried in paper... double check and don't force the fit...

 

[nvrstuk]

Correct, the AOD flexplate is perfect.

Heads up... be careful NOT to get the E4OD or C6 flexplate. Everything is exactly the same except the offset is wrong. It will bottom out the convertor and preload the thrust bearing on the crank.

There IS an AOD flexplate that will bottom out...ask me how I know. The AOD flex plate that bottoms out does so by .060" on a 4r70w.

My build thread on the web site that is no more documents the part # from Summit. I have it buried in paper... double check and don't force the fit...

 

[JKH67302]

Can you drill out 3/8" holes in the heads and retread to 7/16" Just throwing this out... Do not know if head casting will allow this.

Yeah I thought of this too, I was also worried about the casting as well. I was reading my interchange book and it reads like you can use GT40 heads on older blocks. I'll dig some more on this.

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[JKH67302]

There IS an AOD flexplate that will bottom out...ask me how I know. The AOD flex plate that bottoms out does so by .060" on a 4r70w.



My build thread on the web site that is no more documents the part # from Summit. I have it buried in paper... double check and don't force the fit...

Thanks for this info. If you can find the part number that work then that would be really helpful. I appreciate the advice!

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