1966 D300 slant six to 440 swap with NP435

[Zpsull01]

Hello,

I have a 1966 Dodge D300 with a slant 6 and NP435 transmission. We often use the truck and find that it is underpowered for our needs. I have an opportunity at a good running 440 that I have been considering swapping into the truck, but I have found little information on this swap. There are two main areas that I am concerned with. The motor mounts and the bellhousing/clutch.

First for the motor mounts. Will these have to be custom or are there a set out there that will allow this motor to go into this frame?

Secondly, the current bellhousing appears to have multiple bolt patterns it and to me it appears to fit small and big block patterns as well as the slant six pattern. Can anyone confirm this? If that is the case I assume that the flywheel has a different pattern than the six mounting pattern. Will I be able to find a 11” flywheel to bolt to the 440 that will still work with the pressure plate and ring gear for the starter and will the crank pilot size cause any issues?

Thanks in advance for the information. All and any is much appreciated.

Zack

[712edf]

I don't think the bellhousing you have will work with a big block. The most direct "bolt-in" would be a bell from a 383 truck, I believe 1968 is the only year it was offered with the hydraulic bell. 69-later were mechanical.

The 361/413 medium duty bell will fit the 440 block, but won't work with the 440 crank. Usually its a 6 bolt vs 8 bolt issue, plus flange sticks out a different distance.

A bell from a 74-77 361/413 medium duty may work, but you may have to use the flywheel/pressure plate that they came with. Also note medium duty transmissions have larger diameter input shaft & thus use a different clutch disc, so you may be a step ahead to use the transmission & all related parts from the donor truck.

I sorry my response is sort of vague/confusing.

Bucky

[Zpsull01]

Thanks for the information. I am somewhat familiar with the clutch issues. We had to replace the NP435 in our 66 with a unit out of a 68 D500. We were able to find a disc that worked with our 11" pressure plate and fit the splines on the transmission.

Just out of curiosity, will an LA motor bolt to the bellhousing in these trucks in place of the 318A motor or will there be flange distance/flywheel issues?

[712edf]

As far as I know, LA318 & Poly (A) 318 use the same bell.....and probably same flywheel. I'm not 100% certain.
LA360 fits the bell but flywheel has to be balanced with the motor.

Bucky

[Zpsull01]

I was aware of the 360 balancing issues. What about the Hemi's? Didn't they run the LA bolt pattern as well? Including the 392, 426, and the new generation of Hemi's? Do they have the same balancing issues or are they neutral balanced as well? Just trying to figure out what I might be able to simply drop into this at some point.

[712edf]

426 hemi was same bell as B/RB.
I can't say about the old 392, nor anything Dodge made after 2002. I believe V10 & Cummins were different than LA (actually the V8's were Magnum by then).

There is a slant six website that might be able to help.

Bucky

[PwrWgnWalt]

While the 318A bellhousing (hydraulic) will certainly bolt on to a 318LA, the flywheels have different offset distances from the rear of the block. The 318A flywheel has a deeper crank flange, to clear the front 'wall' of the hydraulic bellhousing. The 318A starter also nests deeper into the bellhousing to reach the flywheel's ring gear, since it sits an inch or so further toward the rear of the drivetrain.
Whichever bellhousing you use, use the flywheel and starter for that year's bellhousing. Mods can be made (I put a 360 in my '64 W200), but the above is easiest.

[Roxyflash]

The flywheel is the hardest part to find there are 6 bolt shaped like a bell usually 12 clutch bellhousing are easier to find because they can be had from any hydraulic bell from big block engine

[walktheline]

So just to chime in... The slant six is its own bolt pattern. LA, A, Magnum (3.9, 5.2, 5.9) are pretty much the same (by memory on a swap, I think the Magnum has one bolt thats different location). 3.7, 4.7, 5.7, V10 are the same pattern. 350, 361, 383, 400, 413, 426, 440 share the same pattern. Dont get into old hemis and polys for a swap as their flywheels differ greatly, doable but not really cost or effort effective IMO. Schummacher may have what you're looking for to do a RB swap as mounts go. Bellhousing and flywheel for your 440 can eventually be found on Moparts or the like... Good luck on the swap