This is a bit lengthly, but it contains the specs I was going to use to rebuild my 4.0. I have decided to go with a 5.0 instead for the following reaseons:
1) Cost (It will actually be less expensive to go with the 5.0)
2) More enhancements can be made to the 5.0
3) Modifications to the 4.0 will also require a new Transmission (Either a T5 for Standard or a built up Auto Trans)
4) Better Low end torque (desirable for wheelin)
PS - You DON'T need the expense of Vanir's Forged Pistons for a blower.
Cost For V6 rebuild $3200.00
BBK blower (supercharger) $2700.00
Transmission (T5, bell housing, hydraulic clutch, 4x4 adapter ... $2500.00
New 66mm TB, 75mm MAS, JBA Headers, CAT, Chip, balance Injectors, Oil Cooler, new radiator, other misc stuff - $1400 (it adds up)
Your at $9800.00 (cut out the blower and chip, your under $7000)
PLUS how much is your labor worth?
If you go with Auto Trans and 2 wheel drive you can do it for about $900 less
Engine Rebuild: I figure about 210 HP without blower, probably about 270 with BBK blower, but it will NEVER have the low end torque of a V8. It WILL be a fun street machine .
The higher rebuild cost is due to parts and labor for some extra porting work. Light porting work will be CRITICAL to making this engine work (Don't over work the porting or you will actually get poorer results. You just want light porting done: clean up the radii, Port the bowl and generally clean it up. DON'T enlarge the port volume. Remove the EGR warts from the exhaust side, and clean them up. In looking at the intake manifolds these will be difficult to properly port match. You can't use the gaskets, you would have to use the Fuel rail as a guide. The fuel rail ports are larger on the bottom than on top, but this is what you would want to port match if anything. The other problem is that the fuel rail mounting is a very sloppy fit. I was considering something like alignment pins as a fix. All in all the cost I was quoted wass way too high.
Vanir also warned NOT to use any of the roller lifters on the market for this application. They are expensive, don't do a whole lot for you, and are of poor quality.
If you rebuild the 4.0 you will need to do pretty much everything at one time, especially if you go with a blower. (Also remember, most blower applications require LOWER compression ratio's, 9.0:1 is about the highest you should go)
New Heads - Mahle, or Marnel (There are no Aluminum heads)
Cam: Comp Cam stock replacement # 49-410-8
Rockers: Delta Camshaft rocker kit
Push rods with hardened tips
Pistons: Federal Mogul Hypereutectic (H570P)
Crank, oil pump, rods, crank: OEM replacements
NOTE: If you go with the Vanir Forged Pistons, you must also use the forged rods. ADD $2000.00 to the engine rebuild.
One final note: What are you trying to accomplish? Is the vehicle for fun on the street, take to the track, or take it off road?
Another reason I decided agains the 4.0 with a blower is that blowers don't do all that well off road, in my opinion, they tend to "kick in" just when you DON'T want them to on the trail. On the street is a different story.
Good luck whatever you decide, I'm sure it will be a fun vehicle.
