Truck 318 NP435 to Big Block NP435, how hard?

[TetanusShot]

I love driving my old truck, its a Short Bed 4x4 with an NP435 4spd but the 318 is worn out & too slow. I have a running 400 I was planning on selling & more Gen 2 Hemi stuff than I care to admit.

How much trouble would it be to swap in the 400 or one of my Hemi's?

Looks like a member here is selling the proper bell housing and fork.

Truck is an '86 W100, carb'd.

 

[hopper]

motor mounts, bell housing, & radiator are all that needs changed-bell housing is the hardest thing to find & they are out there. easy job really- I did it 30 yrs ago in a 74 W200 & still have the truck!

 

[TetanusShot]

motor mounts, bell housing, & radiator are all that needs changed-bell housing is the hardest thing to find & they are out there. easy job really- I did it 30 yrs ago in a 74 W200 & still have the truck!

Well that's encouraging to hear, I gotta say this NP435 has about ruined me for driving other 4spds. After driving that gnarly thing all the time, all the other stick shifts just feel numb with no feedback!

Does the clutch need changed too?

 

[moparmarks]

Like stated,
Bellhousing
Radiator
motor mounts.
Also will need BB truck oil pan, dipstick and pick up.
BB truck Exhaust manifolds or headers.
BB truck water pump housing
I have this bell housing for sale. Might have the motor mounts, oil pan, e-manifolds and water pump housing.

 

[moparmarks]

Both SB and BB housing take the 143 tooth flywheel and same clutch. Only difference might the balance of the fly wheel depending on which BB motor you use.

 

[TetanusShot]

I tried to figure out if the current 318 was external or internal balance, but info was inconclusive. I'm interested in your parts, but want to be thorough in my research first.

 

[moparmarks]

Sure good to be thorough.
What year is your truck? Also 2wd or 4wd? There are some differences.

 

[TetanusShot]

1986, 4x4

 

[Kern Dog]

All 318s were internal balance. The 400 will require you to drill balance holes in the existing flywheel.

 

[TetanusShot]

I have a motorhome pan off a 440, would that work?

I also have a spare 22" radiator out of a 383 auto Challenger. If I used this in the truck, it would match up with the car style water pump housing. Is there any reason why that wouldn't work that you guys can think of?

My 400 & spare Hemi have the car style water pump housing.

 

[moparmarks]

Motorhome pan won't work
I'd want bigger than a 22" rad. Never tried a car radiator in a truck.