454 to 4L80E

[C-Moore502]

Right now I have a 6.2 with an SM465 and NP208 in my 84 K20. I am thinking about putting a 454 in it with a 4L80E. My question is what transfer case will fit best and does anyone know what length drive shaft I will need. I won't have much over a weekend to do this swap so I need to have everything ready to go before. Thanks guys you're all life savers!

[Irish_Alley]

I may be wrong on this but the 80e was only in i.d.f. trucks (trucks with cvs) which also had a driver side drop transfer case so if you want one you can a. buy a adapter for one that’s will mate a passenger side drop transfer case to that trans or buy a drivers side drop axle. Now im not completely sure about all this but that’s from what I can think of.

[slammed79]

You'll need a stand alone controler for the 4L80E and making your speedometer work may be tricky.

 I read on another forum that the adapter from the NP241 will let you bolt a NP205 up, but you'll need a NP205 with a 32 spline count input shaft.

 I don't know alot about this sort of swap, but I'd imagine its gonna take a bit more than a weekend to get it done and working right.

[VileZambonie]

I may be wrong on this but the 80e was only in i.d.f. trucks (trucks with cvs)

What is an i.d.f. truck? Is this a truck with CVS?



The 208 or 241 will work.  Driveshaft length will require you to break out a tape measure when it's installed.

[Irish_Alley]

Independent front and with c.v. joints lol

[joesgarage71]

You mean IFS
Independent Front Suspension

[Irish_Alley]

Yes lol. Guess I'm not all there at 2 in the morning lol

[ehjorten]

A NP241 adapter will work for the NP205, but only the 6-bolt circular ones (not the older race-track bolt pattern).  Those are the ones like on my '91 Crew.  They are pretty hard to find.  Just a NP241 will work also.  The Vehicle Speed Sensor (VSS) on the tailshaft of the NP205 will require a stand-alone controller.  Those controllers are pretty expensive (around $1,000).

[1980c10]

.  The Vehicle Speed Sensor (VSS) on the tailshaft of the NP205 will require a stand-alone controller.  Those controllers are pretty expensive (around $1,000).

I've recently searched these and found them between 250-350.
If this is what you are talking about;
http://www.gaugeguys.com/cablex.htm
On my project;
I'm skipping this and will use my gps until I get some motivation to redo my speedometer.

[ehjorten]

I might have mispoke...the stand-alone controller for the 4L80E like the CompuShifts are expensive.  There are probably less expensive solutions.  I have all of the wiring diagrams.  Will have to look at them again.  I would like to do this to my '77 but last time I looked it takes a long time for payback on the investment.

[Captkaos]

4L80E's were available in 1991 HD pickups with TBI, and in 454SS'.  I have one in my 1991 Crew Cab.  The NP241 with the 6 bolt pattern will work on them also.

TCI and Compuware have controllers for these.

[VileZambonie]

In Suburbans as well