Turbo big block, which to use, 413 or 440?

[YellowDodge67]

Looking to build a turbo motor and trying to hold off getting an aftermarket block for a few years. Regardless of which block I get, the basic plan is to do a low fill of the water jackets and a girdle for support and rigidity. The only reason I'm considering the 413 is to lower the displacement a hair to better match the turbo and I heard that the 413's are underbored 440's so the cylinder walls are thicker but have not had that confirmed, so if anyone could chime in on that it'd be much appreciated. My main concern with the 413 is availability and support in the aftermarket compared to 440's on parts such as pistons. Any thoughts and advice would be appreciated,

Thanks,
Jack

 

[66Satellite47]

Don't think 413's have thicker cylinder walls. They were designed smaller bore. You would need to sonic test each block to verify what you have for wall thickness.

 

[Cranky]

Why not just use a 400. It will also take up a bit less room in the engine compartment and parts for it are plentiful.

 

[YellowDodge67]

Why not just use a 400. It will also take up a bit less room in the engine compartment and parts for it are plentiful.

In hindsight may have been a good choice but the fabrication is already done based on an RB so wanted to stay 413/440.

 

[YellowDodge67]

Don't think 413's have thicker cylinder walls. They were designed smaller bore. You would need to sonic test each block to verify what you have for wall thickness.

Thats what I had thought, just saw the "underbored" theory when doing research and wanted to see if anyone had heard of that.

 

[66Satellite47]

Sonic testing gives you an interesting view of production quality. I sonic tested blocks from '66 to '78 and the results were very interesting. Year didn't seem to matter much. Just the specific block. The later '70's 440 blocks were a little bit thinner.

 

[YellowDodge67]

Sonic testing gives you an interesting view of production quality. I sonic tested blocks from '66 to '78 and the results were very interesting. Year didn't seem to matter much. Just the specific block. The later '70's 440 blocks were a little bit thinner.

Are most machine shops capable of doing sonic testing or is more specialized? The engine thats in the car now is a 100% stock 74 or 75 RV motor, that runs ok and is in there mostly to get the bugs worked out with the electronics and getting it running right, didn't want to experiment with a $5000+ built motor. Thats why I'm planning out the new motor to have ready to put in when the existing stocker quits.

 

[Mike67]

Just curious what fabrication have you done that would not work on a 400? Plenum?

 

[mopar 3 B]

Some of the mid and late 440s had more meat on top in the cam area.
If cylinder wall thickness is a concern sleve it and have it over with.

 

[dieseldazzle]

It's gonna spit the crank out the bottom first. I don't think it matters which motor you use but i say the larger motor its simple

 

[Sweet5ltr]

Looking to build a turbo motor and trying to hold off getting an aftermarket block for a few years. Regardless of which block I get, the basic plan is to do a low fill of the water jackets and a girdle for support and rigidity. The only reason I'm considering the 413 is to lower the displacement a hair to better match the turbo and I heard that the 413's are underbored 440's so the cylinder walls are thicker but have not had that confirmed, so if anyone could chime in on that it'd be much appreciated. My main concern with the 413 is availability and support in the aftermarket compared to 440's on parts such as pistons. Any thoughts and advice would be appreciated,

Thanks,
Jack

View attachment 526602

None of the above,

Purchase a 400 low-deck. Save yourself a-l-o-t of pain later on. 400 low-deck will survive with correct ring gap and good internals, go with 400-470 cubes. S480 w/ 1.5 a/r. Will easily make 800+ hp on low boost. A lot of guys are running FiTech EFI 1200 kits now, I ran a CSU blow-through. FiTech was not around when I originally built my setup. It's difficult for me to recommend the RB motors, they're fine for mild-builds, but nothing like what you're trying to achieve with the setup above. Run the RB 413 or 440 until failure, and build a 400 low-deck on the stand.

I have a very good turbo grind sitting on the shelf, Lunati Nitrided Custom Solid Lifter Camshaft (.526/.546 236/243 115LSA). Went through initial break-in, 0 miles. Cost me well over $400, will sell for $200 shipped if you can use it. That includes lifters.

 

[YellowDodge67]

Just curious what fabrication have you done that would not work on a 400? Plenum?

The headers and crossover will have to be modified to fit a low deck (heads are lower and closer together)

 

[YellowDodge67]

None of the above,

Purchase a 400 low-deck. Save yourself a-l-o-t of pain later on. 400 low-deck will survive with correct ring gap and good internals, go with 400-470 cubes. S480 w/ 1.5 a/r. Will easily make 800+ hp on low boost. A lot of guys are running FiTech EFI 1200 kits now, I ran a CSU blow-through. FiTech was not around when I originally built my setup. It's difficult for me to recommend the RB motors, they're fine for mild-builds, but nothing like what you're trying to achieve with the setup above. Run the RB 413 or 440 until failure, and build a 400 low-deck on the stand.

I have a very good turbo grind sitting on the shelf, Lunati Nitrided Custom Solid Lifter Camshaft (.526/.546 236/243 115LSA). Went through initial break-in, 0 miles. Cost me well over $400, will sell for $200 shipped if you can use it. That includes lifters.

Might take you up on the cam but have to talk to my tuner and engine builder first. The car runs and drives other than a few gremlins we're still working out. Has a s475 1.32 a/r. Was originally gonna do a blow-thru carb setup, then was thinking the FiTech 1200 but ended up going with MS3Pro with LS coils, figured it would allow for more flexibilty and room for growth down the road.

 

[Sweet5ltr]

Might take you up on the cam but have to talk to my tuner and engine builder first. The car runs and drives other than a few gremlins we're still working out. Has a s475 1.32 a/r. Was originally gonna do a blow-thru carb setup, then was thinking the FiTech 1200 but ended up going with MS3Pro with LS coils, figured it would allow for more flexibilty and room for growth down the road.

You made the right decision on the fuel supply. With that turbo, you're going to want to go with a stock-stroke 400. That camshaft has nearly the lowest overlap possible; while maintaining adequate duration and lift. I would like to see what your engine builder says.

 

[YellowDodge67]

@Sweet5ltr Yeah me too. I'm gonna talk to my fab guy first to see what would be involved with modifying the exhaust to work with a low deck. Everything is pretty tight under there so moving things around could be pretty involved and honestly they just finished the exhaust work so I'd hate to redo a lot of it in such a short period.

 

[Mike67]

Deck height is the only difference physcally, about 3/4", not huge though. Headers should work, same heads , cross over would probably have to be shortened
Thanks for the answer though, got any pics of your progress?

 

[YellowDodge67]

Deck height is the only difference physcally, about 3/4", not huge though. Headers should work, same heads , cross over would probably have to be shortened
Thanks for the answer though, got any pics of your progress?

I don't have any decent pictures of the final product in the car, in running condition. The picture in the original post is probably the most complete picture I have of it. These pictures are of how the hotside looks outside of the car and how the crossover is run. With the cross over being right above the k-member I think that section would have to be re-done if everything moved down 3/4in due to it bottoming out on the k-member on both the driver's and passenger's sides.

 

[Mike67]

Nice ! I wouldn't think everything would have to move 3/4 as that is based on 90 deg to centerline of the crank, and the angle would probably make it more like 3/8" lower but the width would shrink probably 1".
But I see why you wouldn't want to do it, definitely would be a pita to start over and retro fitting everything. Very cool project, have you started a build thread?

 

[YellowDodge67]

Nice ! I wouldn't think everything would have to move 3/4 as that is based on 90 deg to centerline of the crank, and the angle would probably make it more like 3/8" lower but the width would shrink probably 1".
But I see why you wouldn't want to do it, definitely would be a pita to start over and retro fitting everything. Very cool project, have you started a build thread?

Thank you, no I wish I had taken more pictures and documented more of the progress. I had a shop do the majority of the work because my welding skills leave alot to be desired but after the last couple issues are resolved it should be a pretty cool driver. I'll hopefully have a new motor set up for next spring so I can actually lean on it and being set up for flex-fuel I'm anxious to see what e85 can offer.

 

[19polara64]

It’s not that a 413 is an underbored 440. It’s that you could bore a 413 to 426 (.0625 overbore). You have to really watch core shift. I have one. I’ve also heard that it might run hot. We’ll see I guess. Should be running next year.