I have a 2002 F-150 Supercrew with a 4.6L and a 4R70W Tranny. I am installing a 2003 5.4 Lightning motor and using the same trans. I had to order a different flywheel for the 5.4 since the one from the 4.6 didn't fit. As we were trying to mate the motor to the trans, we noticed that the 4 bolt converter pattern on the trans was different from the 4 bolt pattern on the flywheel. Are there different converter sizes for different applications of the 4R70W trans? Any help would be appreciated.

 

L motor takes a 4R100. 4R70 might not be enough for the Lightning motor, that's why they used a Super-Duty Transmission

 

YEP what he said

Sal of PSP swapped his 4.6 to a 5.4 in his police interceptor and originally used the 4R70 (lasted like 1 week).
He then either rebuilt it much stronger or swapped to a 4R100, either way he has the answer you seek powersurgeperf@aol.com

 

Why didn't the 4.6 flywheel fit? It should have went right on. Nothing different between them crankshaft wise. The Lightning uses the 6 bolt flywheel, but you can use one from a regular truck to get the 4 bolt. The 4R70 does have a smaller converter pattern, but like I said, it should have went on the 5.4 no problem.

 

The 2003 Lightning by no means uses a 6 bolt flywheel. A Lighting uses an 8 bolt flywheel with a 6 bolt converter pattern. A 4.6 uses a 6 bolt flywheel with a 4 bolt converter pattern.

 

Sorry, I wasn't too clear on my post. I was talking converter bolt pattern, not crankshaft bolt pattern. All 5.4s and all forged crank 4.6s use an 8 bolt crank. Only cast crank 4.6 motors use a 6 bolt pattern.

You can get an SFI modular flywheel from Performance Automatic. It's drilled for the two different 4 bolt converter patterns so that will work for you. Or, you can just double drill the flywheel you have.

 

well that must have been what I had, a cast crank 4.6, because it only had six bolts for the flywheel, and 4 for the converter. But I ordered a flywheel from Ford Motorsports, and it was for the eight bolt crank and 4 bolt converter, but the converter bolts and the holes on the flywheel didn't match up, looks like I need a smaller converter bolt pattern. Any suggestions?

 

The PA flywheel I mentioned has both the large and small 4 bolt pattern. I used that on my Lightning powered Interceptor with the 4R70W.

 

yea, that sounds like what I need. But I am waiting to talk to Alan at Dirty Dog to see what he suggests as far as another converter goes. I may just end up going with the smaller stock converter for this, or may even get one of his rebuilt stock ones. According to the JMod article, the 4R70W tranny came with two different size converters and the smaller one is less prone to ballooning at higher RPM's. So maybe I'll get Alan to rebuild me one of those with decent parts. I dont want a super high stall, I am going to be daily driving this deal, and towing my boat to the water, (about 1/2 a mile) on occassion, so hopefully I can just keep the flywheel I have and go ahead and get the upgraded converter. I also ordered a valve body plate kit from Mike Dunn that should help with shifts and preserve the trans against the L motor.