408 stroker owners, more advice....

[WARDOG]

I received my engine yesterday.
The Dyno tests recorded 425 HP & 500 Torque!

For those that did their swap, did you replace the motor mounts or are did you keep stock?
What aftermarket mounts did you switch?
I plan on Centerforce clutch & flywheel.

I am replacing the D20 output shaft with the WH beefier one.

While I have everything torn apart, what other areas have you discovered to show weaknesses over time?.

I am running rebuilt NP 435, rebuilt D20, new 31 spline Chromoly axles, 4:88 gears with ARB lockers w/ 35 tires. I have the FAST E.F.I.

Thanks-

 

[Broncobowsher]

Many with lesser engines than that have replaced the motor mounts. Some complain that the extreme mounts raise the engine, not enough for me to worry about. I used them and they worked perfectly.

Other weaknesses, axle wrap. Good torque arm takes care of that.

 

[markw]

My numbers are just about the same on the dyno but I don't have the Bronco running yet. I used the extreme mounts as well. Even with a 1" BL I have to use an after market hood to clear even with the holes elongated to drop it as far as possible. All Ford FI GT lower and Explorer upper. Maybe we goofed and welded the mounts too high.

 

[Broncobowsher]

I remember figuring it would take 1¼~1½" of body lift to clear the Ford lighting/Explorer EFI intake on a 351

 

[markw]

You're right, it doesn't fit well with the extreme mounts. On the other hand I have only 3.5" lift and a high pinion D44, extra capacity oil and trans pans so the mounts give me some more clearance there. Change one thing change everything I guess.

 

[LowCountryEB]

Did you order a crate motor? Or custom build?

 

[C Saporito]

They are much stronger mounts, the issue I had was the motor kind of angles down making the front transfer case yoke angle a little worse. You can shim the transfer case mounts to match the motor height but will need a body lift also. If you don't have a big suspension lift it wouldn't be a problem.

 

[WARDOG]

LowCountry- It is a crate motor.
I answered some of my own questions since the original posting.

Motor mounts - Went with the WH Extreme. No fitment issues and they are beefy.
I replaced the D20 output shaft with the Advanced Adapters Output shaft. There is a considerable difference in strength. It added 1 1/2" to the length of the D20 though. I think my rear driveshaft is still short enough though.
I welded in a WH Wrap Trap. Seems to be a beefy and simple fix for upcoming axle wrap.

I have had a few slow downs in the build. I am constantly finding problems created by PO which just takes time to fix. Currently I am repairing the rear frame horns which were smashed in by PO and welded in some fence posts? to make a half-ass bumper work. I have to finish the welding before putting fuel in the rear tank.
Also I am switching to FAST EZ EFI. That was an expensive endeavor. The added cost of the unit, tank, in-tank pump, AN - fittings, fuel line, Fuel pressure Regulator was way more than I anticipated.
I should start the motor this Sunday, Sep. 6th. I have to rig up an exhaust to mount the O2 sensor so I can drive it to the exhaust shop the following Tuesday.

I plan on posting a build thread with pics after it is running and the bugs are figured out.
I budgeted 4 weeks to do the swap but I just started week 8.

 

[BRONKEN]

Any update? I'm getting ready to do a 408 stroker and curious to see how your build goes. I'm concerned that the D20 with the new shaft will hold up to the HP, also if the 31 spline axles can take some abuse or change to 35 spline and be done with it. What was your reason to go FI and not stay with a carb?

Ken

 

[LowCountryEB]

Which crate motor did you go with? Can you please list the link? Also, what is the D20? And what's the cost to upgrade?

 

[nvrstuk]

Bronken, you sig says 35's... thr 31's are tough but bigger is better with torque. I literally ate D20's when i was running ZF/203/d20... cases, gear teeth, but my 300M output shaft never failed. 9" rears too...BBtorque and then add stoopid gear reduction and stuff breaks...just does!