Need info on 383/400 swap

[Headrope]

I have the opportunity to get a 400 out of a Ram Charger. I don't know what year it is (76, I think he said) but it's supposedly a strong runner that doesn't smoke, knock, etc. I'll find out when I go to hear it run. The plan is to swap it into my '66 - in place of the 383, which has taken up smoking.

I'm guessing the oil pan and exhaust manifolds may be an issue with the 400. I've read and been told that all the bolt-on stuff is interchangible between 383 and 400s. Is the same still true if one is out of a car and one is out of a truck?

Has anyone swapped a 400 into a first gen?

Any help appreciated.

[cudaken]

 You will need to cahange the converter. 383 is a steel crank and 400 is a cast crank. Balnces is driffrent, 400 has a counter weight on the converter, make sure you uses the balancer that is on the 400 as well.

I think, that B&M makes a flex plate that will let you use the 383 converter with the 400. That is assumeing it a 727 Charger. To be honest, you are sort of doing it backwards. Most people do it the other way around, cast to steel. Nothing wrong with a cast crank.

One other thing you could do, have the 383 crank turned. Use new main and rods bearings and will drop into the 400 and use the 383 balancer and converter.

                           Cuda Ken

[Headrope]

Wow. I got caught up in the excitement and forgot all about the transmission end of the process. Cudaken saves my butt yet again. Thank you, sir.

I'm intentionally working backwards. The plan now is to drop in the 400 so I can enjoy my car for a few weeks this year (I spent the summer rebuilding the 383 but didn't replace the piston rings while it was apart). I was stupid and temporarily lost the faith.

Those of you reading that are in the middle of - or about to undertake - your first rebuild: replace the piston rings while everything is apart - regardless of what you're told.

The new plan is to run the 400 and re-rebuild the 383. Once the 383 is back in I'll build the snot out of the 400 - which is something I've always wanted to do (a 440 would be the ultimate but I've got so many go-fast parts already for a B block it just wouldn't make financial sense).

The 383 has a brand spanking new crank. The trans (yep, it's a 727) was just rebuilt and has a brand spanking new torque converter. Looks like I get to go shopping for the B&M adapter flexplate.

Thanks again Cudaken.

[Ghoste]

But the 400 converter is balanced so if you use the new converter even with the B&M flexplate, you'll have problems.

[cudaken]

But the 400 converter is balanced so if you use the new converter even with the B&M flexplate, you'll have problems.

Head rope, your making me blush. As far as ghoste posting I am not sure how the B&M flex plate works. If it so you can a steel crank in a cast crank car, or a cast crank in a steek crand car.

Easy way would be either use the 400 converter that was be hined the 400 or pick up a rebulit converter. If you can find a local Trans Suppily House you should be able to get a rebulit converter for around $100.00. I got mine for $50.00 but been 5 years. 74 Polices car 400 converter will give you a 2400 stall.

If you where to use the one that was used with the 400, have it flushed! Don't need any stuff from a unknown 727 in yours.


                                Cuda Ken

[RD]

do not forget to swap oil pans/pickups and you will need to use your 383 motor mounts (obviously).  I have a 400 weighted converter at my house if you need one.

to flush a converter, get 2 quarts of mineral spirits, pour into converter (after it has been emptied as much as possible of all tranny fluid), take an old input shaft from a 727 tranny and place the input shaft in the torque converter, spin the thing around and round like you are wanting to make the tq 'verter dizzy.  unscrew plug in front of tq 'verter and remove all the fluid.  repeat at least twice.

[Ghoste]

Hey Ken, what I was referring to was independent of the flexplate.  The cast cranks are not balanced internally, they are balanced front and rear by the damper and converter (as you already know) so changing the flexplate won't do anything for engine balance.  He has to use the externally balanced converter as well.

[firefighter3931]

  He has to use the externally balanced converter as well.

That isn't necessarily true, B&M makes a flexplate that allows for a neutral balance converter on an externally balanced motor. The B&M part # is 10237 for the cast crank/neutral balance converter.

The other option which is one i like better : Take the forged crank and rods out of the 383 and get a nice set of pistons custom made for the 400. Then you have the best of both worlds, larger bore and more displacement. A set of custom slugs is usually around $50.00 more than something that is off the shelf. You can then dial in the static compression exactly where you want it. A closed chamber head with a zero deck piston is the way to go for pump gas on the street. Better fuel burn and no predetonation to worry about. A tight quench 9.5:1 motor with iron heads is safe for pump gas.

Ron

[cudaken]

 Ron, he is on the cheap. That is why he is thinking about the 400. Just wants a quick fix so he can drive his Charger.

Ghoste, as Ron pointed out that is why I said to get a B&M Flew plate. I know of them, just never had need of one.

                                 Cuda Ken

[Ghoste]

I learned something.  I thought the B&M deal was just to use a variety of converters on one flexplate and still have it SFI approved.  Didn't know that about the neutral balance option.

[John_Kunkel]

The plan is to swap it into my '66 - in place of the 383, which has taken up smoking.

If your '66 still has the original transmission, forget about using the 400 converter because '66 is the last year of the old 19 spline input shaft; the 400 and all after '66 have the 24 spline input shaft.

The two alternatives are the B&M flexplate and your old '66 converter or change the input shaft to accept the '67 and later converter and use a weighted 400 converter.

[cudaken]

 John, I never knew that but that what is great about this site. Never knew the old RB 383 crank would not work with the newer trans or there where driffrent splines for the Trans. But all my stuff have been 68 or newer.

                                                                 Cuda Ken

Head rope, get the flex plate.

[Ghoste]

I wish John would write a book.  With his collection of photos comparing parts.

[Headrope]

The plan is to swap it into my '66 - in place of the 383, which has taken up smoking.

If your '66 still has the original transmission, forget about using the 400 converter because '66 is the last year of the old 19 spline input shaft; the 400 and all after '66 have the 24 spline input shaft.

The two alternatives are the B&M flexplate and your old '66 converter or change the input shaft to accept the '67 and later converter and use a weighted 400 converter.

I had the shaft changed when the tranny was rebuilt. It is a '66 727, but with a 24 spline shaft in case I ever wanted to change converters. I've got a brand new converter in there for the 383 so will probably go with the B&M flexplate.

Thanks everyone for the input. It's amazing the amount of knowledge in here.