Hi guys,

I'm new to the forums and new to restoration\rebuilding projects. So any tips and pointers would be awesome.

I just purchased a 440 RB engine (I think?). The casting number is 3698830 400 5.

It has been rebuilt and now has a 30 over bore. I'm planning on putting this into a 1972 Plymouth Duster which was modded for a big block with a 727 trans. It use to have a 383 big block in it.

Other then that I do not know to much about this engine and I'm trying to find details but online searches aren't providing much results.

I've read multiple sites that said RB engines all have cast cranks? But then I read other sources saying that 418-440 have forged steel cranks? Anyone know which it is? Also according the casting number the block states it is a 400?? but the prefix says 440?!?!?

I'm also looking to perform a few upgrades to get some more ponies out of it. Any recommendations?

The heads are off of it atm, only thing done is core, crank, cam and pistons. Which according to previous owner are all stock.

While its open I have a chance to do some changes to it. Was thinking of replacing the cam and get some good heads for it etc... any recommendations?

 

What's the casting date on the block?

 

I dont have physical access to the block yet. It's currently being shipped to me.

I have the following pictures, maybe someone can figure it from the pics. However I believe it's from 73.

 

That's not an RB BLOCK!

 

Are you sure?

http://www.mopar1.us/bigblock.html

3698 830 shows here as a RB.

Even if its just a B that's actually better for me. No fab work and I can just drop it into my car.

If its not an RB, than it's gotta a B. But how are you determining it is not an RB?

 

YES!!!

 

Looks to be a B, 400 sumthing.

 

yeah thats what I thought from the pictures but the casting number say different... : / Also weren't 400s small blocks? I thought the 402 was big block.

How can I figure out exactly what it is?

 

The last series of your numbers tell it all a 400 low deck and it would have a cast crank.. There are NO 400 cu in small blocks the biggest is a 360. An aftermarket engine can be built to a 402 mall block with a stroker kit. You need to find out exactly which 400 you have because it is externally balanced

 

Ok thanks for the heads up. I'll know more once the parts are delivered and I can pull information off it.

I'll reply back with more info.

 

You're thinking Chevy.

 

The block looks to be a 400 the pistons are .030 over, it is possible that it has a 440 crank in it?

 

Yeah you are right. I was thinking Chevy... : /

And about the 440 crank. That's a good question. I'll have to check it out as well. I purchased this thing on ebay and the previous owner said it came out of a 1973 Challenger. But who knows what the guy with the Challenger did to it. It was rebuilt before it was purchased by the person I just bought it from. I don't think he knows to much about it other then it was rebuilt and it turns over...

But because of that I got it for dirt cheap with the trans.

 

That's a 400 B Block.....
When you get it you can get the casting number off the crank and find out what it is from there if any changes were made.
But the guy that shot paint all over that engine !!!! I would slap him...
For me that engine has to come all apart for cleaning and re-inspection...
Check and see how far down in the hole those pistons are?
Just my 2 cents... Lets see what you got when it shows up?

 

Hi Bob, yes that would be the best idea. I'm with you on that. Especially when I saw paint in the top of the piston cylinder on the pictures...

I should have it delivered on the 8th so I'll be able to pull off those numbers and add more information then!

Thanks!

 

Keep Us posted....

 

I don't have the parts in yet (should be in by the 9th). However I did a search on a few different makers and it looks to be a Dodge 400 from 1973-78.

http://www.stockmopar.com/mopar-engi...g-numbers.html

Casting# 3698630

So far it's the only one that shows a 400 block.

I'll verify when parts come in.

 

The 400 rite next to the casing number..... That means it is a 400.... At least the block anyway....

 

I searched the numbers on the pistons and came up with zip. The block is a good base for a stroker kit, 500" or 512".

 

Wasn't the 400 blocks already kinda close to it's limits in block strength to performance?

I heard that simply doing a 40-60 over on them was enough to start overheating problems.

Will I be able to do a stroker kit with a 30 over bore already done you think?

 

.030 over and a 4.25 crank = 512"
.030 over and a 4.15 crank = 500"
.030 over and a 3.75 crank = 451" 440 crank

Go to 440source.com

The pistons in it now are probably cast, low compression stock replacements. Not a good choice for performance use.

 

Awesome thanks, very helpful!

Are SCAT cranks any good? I can get one at 4.25 for dirt cheap from a buddy.

 

Yes, have a 4.15 in my 500" 440. It was built in 92 lots of pass's and street miles .

 

Is it for a 440 or a 400? Two different journal sizes.

 

I believe its a 454 Main Journal. I think it is also internally balanced. What does that means for this engine that is externally balanced currently?

 

The mains are 2.20 or 2.75, rods are probably Chevy size.

 

I believe it is this. Its 2.200

http://www.ebay.com/itm/Scat-945425-...pVehT9&vxp=mtr

 

Looks to be a Chevy crank.

 

Yeah that one is. But the one my buddy has is similar in specs but for Dodge. I'll have to get more info from him on it.