A833 OD or 727 behind a 440. Suggestions and questions
- Thread starter my5thmopar
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The achile’s heal is the aluminum case with the sloppy “floating” countershaft. I typically swap out the case for an early cast iron case from 64 or 65 with clearance for the large in size 1st gear. Get a countershaft for that case and that is as good as it gets. You should have the good gear set, instead of the later cast gear set in the later truck O/D.
If your 440 has the cast crank it wont have the pilot hole drilled, something else to consider if you haven't already. I think the OD 4 speed with one of those motors would be a good combo. I love the old sweptlines.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Matt
with 255s, you'll never break anything in that box with the exception of the little od gear.
The Achilles heel is the very wide splits; .540 and .599, which only becomes so with a high-reving high-rpm-cammed engine. And really the 1-2 is the worst. So I wouldn't run it with something like a low-compression, small displacement engine with something like a 268 or bigger cam, unless it also has big rear gears.
I ran it with two engines and 4 cams and many rear gears, and the only way thru that 1-2 split, performance wise speaking, was with big rear gears so the engine could pull in second.
With a 340 or less cubes;about the smallest overall second gear you would want to run is 6.06 corrected to 24" tire as stated in post 16. That gives you something to play with.With 255/60-15s coming in at 27" tall, that would be 4.10s;( 4.10x1.67x12/13.5=6.086). These will get you 32mph@2720rpm, so your engine better have some power down there. An 8/1- 318 with a 268* cam won't pull that real briskly. In fact a 318 with a 268* won't pull that with hardly any Scr. So a downshift would be required and the the engine will be screaming at 5040..... for about a half of a second and then you just have to put it back into second,anyway. That is the Achilles heel,right there.
A high-torque 367 with something like that 268* cam and plenty of compression will muscle it's way outta that 2720 hole,but not with any authority. I ended up with 4.88s for a while but first gear was ridiculously useless, so I tried 4.30s. That put the Rs up to 32mph@2850, and my 367 was ok with that at 10.9Scr/185psi/aluminum heads/164VP.
I think a stroker would be happy with down to 3.91s, so long as it is well-engineered; ie; similar pressure and aluminum heads, will get you a VP about 13% higher, so you can run 13% less gear than the 4.30s, so I get 3.81s . With 3.91s you could cruze at 65=2300 in .73od If you already have 3.73s installed, I would try them. 65mph will be 2200rpm
If you decide 360 cubes then put aluminum heads on it and pump the pressure waaay up; I run 10.9Scr on 87E10@ from 175 to 185psi. 175psi is a cheap easy build. 185 requires a zero-deck to a little pop-up,so machining is required.
If you have traction issues, then ignore EVERYTHING i just said, and run whatever you want
BUT
Just remember that it's a 3+1 trans. When you hit third gear,
STOP!
Remember.
Gently put it into overdrive.
with 255s, you'll never break anything in that box with the exception of the little od gear.
The Achilles heel is the very wide splits; .540 and .599, which only becomes so with a high-reving high-rpm-cammed engine. And really the 1-2 is the worst. So I wouldn't run it with something like a low-compression, small displacement engine with something like a 268 or bigger cam, unless it also has big rear gears.
I ran it with two engines and 4 cams and many rear gears, and the only way thru that 1-2 split, performance wise speaking, was with big rear gears so the engine could pull in second.
With a 340 or less cubes;about the smallest overall second gear you would want to run is 6.06 corrected to 24" tire as stated in post 16. That gives you something to play with.With 255/60-15s coming in at 27" tall, that would be 4.10s;( 4.10x1.67x12/13.5=6.086). These will get you 32mph@2720rpm, so your engine better have some power down there. An 8/1- 318 with a 268* cam won't pull that real briskly. In fact a 318 with a 268* won't pull that with hardly any Scr. So a downshift would be required and the the engine will be screaming at 5040..... for about a half of a second and then you just have to put it back into second,anyway. That is the Achilles heel,right there.
A high-torque 367 with something like that 268* cam and plenty of compression will muscle it's way outta that 2720 hole,but not with any authority. I ended up with 4.88s for a while but first gear was ridiculously useless, so I tried 4.30s. That put the Rs up to 32mph@2850, and my 367 was ok with that at 10.9Scr/185psi/aluminum heads/164VP.
I think a stroker would be happy with down to 3.91s, so long as it is well-engineered; ie; similar pressure and aluminum heads, will get you a VP about 13% higher, so you can run 13% less gear than the 4.30s, so I get 3.81s . With 3.91s you could cruze at 65=2300 in .73od If you already have 3.73s installed, I would try them. 65mph will be 2200rpm
If you decide 360 cubes then put aluminum heads on it and pump the pressure waaay up; I run 10.9Scr on 87E10@ from 175 to 185psi. 175psi is a cheap easy build. 185 requires a zero-deck to a little pop-up,so machining is required.
If you have traction issues, then ignore EVERYTHING i just said, and run whatever you want
BUT
Just remember that it's a 3+1 trans. When you hit third gear,
STOP!
Remember.
Gently put it into overdrive.
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I read the whole thread to see if someone was going to point this out. Cast crank engines were not drilled to except the long input shaft. Drilling is not an option as some of the cast cranks were so porous they would leak oil out the drilled pilot shaft hole. Wheeler engines tried this in the 70's and it didn't work.
There may be a way to do it with a bearing in the torque converter snout recess and shorten up the input shaft accordingly. I don't think the factory ever put a manual trans on a cast crank big block. All the cast 400 and 440 cranks I have, and all the other ones I've seen are not drilled, but I have never seen a 318 crank that wasn't... cast or forged.
Your right there is a way to do it. But it involves cutting the input shaft.
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