69 Coronet 383 2bbl to a 440 with 450 HP....what has to change in this set up?

My 69 Coronet came with 383 2bbl and my thoughts after reading all the info here is that this may not be as simple a swap as I envisioned. The whole drive train will be under a lot more strain from the 727 tranny on back to the small pinion 8 3/4 rear end. I have several questions:
1 Will a 440 bolt up the same as the 383? Clearance and motor mounts...
2 Is there a difference in the 727 built behind this weaker 383 and the 440 4bbl?
3 Without going to a Dana, can I use a larger diameter pinion plus stronger axles and feel secure that it will hold together with some normal "street " fun?
4 Will I be able to use all the PS pump,alternator,AC ...etc and their brackets from the 383 and bolt right on the 440?

I was under the impression that this swap would be fairly straight forward and that the auxilary components would bolt us as well as the "fit' in the engine bay and with the rest of the drive train would need little more then upgrades to handle the torque and horse power difference. Am I that far off in my thinking?

You are in luck brother.... this IS an easy swap.

1. The 440 will bolt up using everything you already have. There "might" (maybe) be a teeny tiny issue with bolting your exhaust back up since the 440 is maybe an inch (?) wider & taller, so your pipes might not be "exact" - $50 at any muffler shop TOPS (the exhaust might bolt up perfectly as it did for me when I did this same swap).
2. The 727's are exactly the same in 383's and 440's
3. You don't need a Dana & probably don't need hardened axles as long as you don't run slicks. My 440 has a 250-shot of nitrous & stock axles and I've never had an issue with my 8-3/4" rear end in over 30 yrs. (no slicks though)
4. You can use every bracket from the 383 on your 440.

Let's see.....
1. You "might" need to modify/change the throttle cable (not sure of the length difference, if any, between a 2bbl & 4bbl.
2. I think you'll need a different air cleaner (I "think" the 4bbl. carb needs a bigger baseplate hole)

I think that's it & some more knowledgeable people on here will probably chime in with some tiny details I might have missed. GET THAT CHERRY PICKER OUT AND DROP THAT PUPPY IN THERE!

Fantastic! I have dealt with chebbies for a long time, 73 was my last Mopar so I wasn't familiar. Good to hear I am in the ball park and the changes you mentioned are ones I was anticipating. Thanks for lining me out, time to start lightening up that engine bay.

just bolt it in and go.

Keep an eye on your cooling system. My 383 Coronet came with a 22" radiator and with the 440 it was stressing the system during the summer. I've since gone to a 26" radiator, however to align the rad opening you have to swap out the passenger side mount, which requires drilling the welds on the original and welding in the replacement panel. Some guys have kept the 22" rad mount with the 26" radiator with no issues.

The 383 2bbl. 727 has 3 pinnion carriers, and valve body pressures are different, and will allow more slippage,witch will allow 440 to burn clutchs up on hard accelleration, and carriers will eventualy let go.

Appreciate the radiator tip CoronetDarter as well as the heads up on the tranny badlite. Can I get the 383 / 727 upgraded to take up the slack or is this a new format all together?

Get a 440 727 Transmission, they are well suited for the application. Then have it rebuilt to the heavier specs.

So, I am hearing that a 440 / 727 is different enough that I should start out with that compared to the upgrade cost of the 383/727? Just trying to clarify what I think I am hearing....that the cost of upgrade would be better spent if I just rebuilt a 440/727.

Mocajava said:

So, I am hearing that a 440 / 727 is different enough that I should start out with that compared to the upgrade cost of the 383/727? Just trying to clarify what I think I am hearing....that the cost of upgrade would be better spent if I just rebuilt a 440/727.

Click to expand...

You can get your present TF built "heavier." Frankly the main thing is at minimum a shift kit to stiffen up shifts.