Transplant consultation

Oldiron440

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I agree, your talking a large bill here.
You will spend as much on labor as parts and assembly's.
 

XfbodyX

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Another brief thought, get a cam ground or a good core reground to better fit your needs and driving habits, a six actually responds better to a cam swap then alot of V8-s do. A good 2bbl, a good ex system, youd be far far ahead on the wallet.

You got to remember your / is a "Lets put it in everything" type motor, taylor it to your needs.
 
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BudW

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In case you didn’t know, the Gear Venders “O/D add-on” bolts onto the rear of your existing transmission. Actually, to allow you to reuse your existing transmission mount/crossmember, GV (Gear Venders) includes a longer tail housing. At the end of the tail housing, you bolt on their gear splitter and it does extend the length of the transmission assembly quite a bit.
The propeller shaft will need to be shortened and, in some cases, the floorpan may need to be “massaged” to make it fit.

aghr4sm - Gearvendors (part number 3DFS833G)
The picture on Gear Venders website for A833. The gear splitter will, in effect, allows you to use 8 forward gears.
a883_Kit-lg7.jpg


This is an A833 (lower half of picture). The GV extension and unit is listed above (to give an idea on how much longer things will be).
iuSFOWMD51.jpg


An GV unit installed on a B-body.
727 GV.jpg

The propeller shaft is on right side of picture. The A833 case is not quite shown, but would be just off of Left side of picture.

I’m not familiar with the Commando unit he is talking about (I don’t think …) so can’t comment about it.
BudW
 

Camtron

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There’s so many bolt on power options available for a /, I’d stick with it. You’ll be able to get everything you want out of it without doing a swap and not make too bad a dent in the ol pocket book.
My uncle has a 70 duster with a / he wants to swap out for a 340...but it’s a slant car so I always try to talk him into stroker kits and forced induction and such lol I also really like the novelty of a / that can spank your average v8

6F5A3154-D8AD-470B-B7A7-216F58C49BF3.jpeg
 

AJ/FormS

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Altho 8 gears are correct for the overdrive box,(7 useable ones) just try running that combo at 65=1350rpm with 2.94s; that ain't going to happen.
The ratios are 3.09-2.41-1.67-1.30-1.00-.78od/.73-.57od. (GV in red)
I ran this exact combo behind a small-cam 367 and was rewarded with phenomenal fuel mileage.
You cannot run this with 2.94s and a slanty. Nor would you want to . To run that, your slanty might pull double od at maybe 1900 rpm, I'm guessing even that is gonna be tough. And that would require 4.10s in the back.
Ok so 4.10 s would do it.
Buuuuut how is that (4.10s and GVod) useful with a slanty, IN OY?
I'm guessing Op is not gonna rev this old girl much past 3600, and you know the slanty has a pretty flat torque curve. So now with 4.10s the slanty is gonna blast thru 3.09 first gear pretty fast,going into second at what was it? oh yeah, 23 mph@1944rpm, and OP is not that unhappy with second the way it is now, so with 4.10s it's gonna be much much better, and with a 6.84 road gear it'd gonna have a very significant improvement at the bottom of second, which only gets better with increased speed. Second goes to 42@3600. And now, on the shift, is where the slanty with the current gears is suffering. But with the current gears (assumed to be 3.23s) the car is doing about 54mph when it hits third at 2155rpm , so of course it's gonna struggle, cuz now the slanty is starting push wind. But with 4.10s the speed is brought down to 44 mpg @2155, and by 54, the Rs will be up to 2750, just about 600 rpm higher, so the engine is getting up on the cam now. And it only has 11 mph left to pull, hitting 65=3310, still not at peak power, but close to it, so it ain't, IMO, gonna be any faster splitting those gears, certainly not worth the Buy-in. And this box already has a .73 od in it pulling 65=2500, so I still can't see the GVod as being particularly useful.
Now, if you pump up the slanty with a big cam to rev it to 5000 or better, now the GVod could be useful............. cuz you would,(or at least I would) pitch that A833od box away and use the regular box with the GVod, and still the 4.10s,lol.
Imo, the usefulness of the GVod is severely limited by the very short operating rpm of the stock slanty, and very low hiway gears. And while 4.10s improves the picture, IMO the GVod buy-in is just not worth the minor improvement.
The bottom-line IMO is that the small operating rpm and the extra-wide 4-speed ratios, together with hiway gears; are a doomed-for-performance combo.

Going back to;
"I ran this exact combo behind a small-cam 367 and was rewarded with phenomenal fuel mileage."
That small cam was a 223*@.050, and I had the engine set up to rev as high as 7000, even tho the power peak was down at about 5000/5200. That's how I made this work for me. With 3.55s; 6200 was was 45mph, and then the split dropped the Rs to 4780 and then it ran up to 60=6400 in first-over. And then cruising at 65 was 1630, in double-od..
This is where the GVod really shines.
If you got the dough for a GVod at ~ 3000/3500 installed; you might as well drop a Magnum in there instead,to pull the current hiway gear combo(and make mine a 5.9). You will get Waaaaaay more bang for your buck. There is only so much you can do with 100/125 hp.
But for a quick test, slam a "regular" box in there and see how you like it;
or just get some 4.10s in there. I heard a Jeep rearend practically falls into there, and I heard they are plentiful and cheap, I heard.
I'd lend you my stuff but, I fear you'd like it so much that I might never get it back. Plus the shipping would kill us.:(
 
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Aspen500

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I'd love to put a Gear Vendors on my Aspen but there's something that prevents it. I forget what that is,,,,,,,,,,oh yeah, now I remember, it's called $$$$$$$$.:(

My car originally had a S6 (90hp E24) and 4-spd O/D with 3.23 gears and trying to use O/D on anything but a level highway was impossible at the then speed limit of 55 mph (remember those years?) Come to a hill, gas pedal to the floor and MAYBE maintain speed. More often than not, a shift to 3rd was necessary as the speed started decreasing. Add in a head wind and forget about it. Anything under 55 and O/D might as well not have even existed. Can't imagine it with 2.94 gears!
 

Oldiron440

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There might be a day when my Volare gets a GV but I'd like to build a turbo 400 for it first.
 

8T2TOP

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Waste of time & effort...
Just hype out /6 can go semi wild to gonzo..
Better than swapping EVERYTHING then might as well just find a V8 car...
 

old yellow 78

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You guys are presenting so many options, my head is spinning! :eek:
I am surprised about the number of positive comments about just reworking the /6, and pleased too! I am starting to think that it would be much less work, money, and time to simply work on the /6 than to swap it out. Also, I really like the idea of keeping the original engine in OY. And, it would be pretty cool, and more unusual, to have a tweaked /6 under the hood too instead of a more traditional V8. :cool: All the comments above show the huge number of possibilities! :)
 

old yellow 78

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that is a nice pickup. I’d have a frown if someone parted out the vehicle.
It is nice, but not as nice as it looks in the pic. It is a salvage title, and as close as we can figure, it was wrecked when almost new in the front passenger side. The frame has been replaced and re-welded up to the passenger floor area. The entire truck is not as tight as it should be. If you look, you can tell the grille is aftermarket with the "Dodge" imprint missing and an incorrect earlier "Dodge" hood emblem placed above it. That being said, it only has about 70K original miles on it and the interior is really very nice. Not a fancy truck, but a good weekend hauler. The Magnum though is the best thing about it. It MOVES! and sounds great doing it! There are no real plans to part it out at this point, but when the body does age out, the Magnum will stay behind. ;)
 

AJ/FormS

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How would I tell what gear ratio I have in my 8 1/4 differential now? How would I go about changing that if needed?
The easiest way is to drive it up into high gear and read the rpm at 60mph; then back-calculate from the tire size.
Here is an example; with 205/75-14s on it, which are about 26.1 " tall, or any similar tall tire, the rpm at 60mph in loc-up mode, (Without lock-up, the rpm could be maybe 3% higher).
with 3.23s would be 2496 rpm.
With 2.94s I get 2272
with 2.73s it is 2110
But with 2.45s the rpm would be 1893.
With 2.20s it would be 1700
As you can see the difference in each case is about 200rpm.

The Formula is; Mph= (rpm x tc) divided by (1056 x R1 x R2)
Where tc is tire roll out (could be diameter x 3.1416), and
1056 is a constant that converts feet, inches, and such, to mph.
R1 is the rear gear ratio, and R2 would be the overdrive ratio, if any.

For this to work, the speed-O has to be accurate., or you can drive whatever speed it takes to achieve one mile in one minute, and ignore the speed-O actual indicated number.
 

old yellow 78

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Them boys, “down unda” know how to spice up a /.
Yikes! They know how to charge for it too! Nice stuff but $$$$$$$
Another brief thought, get a cam ground or a good core reground to better fit your needs and driving habits, a six actually responds better to a cam swap then alot of V8-s do. A good 2bbl, a good ex system, youd be far far ahead on the wallet.
Waste of time & effort...
Just hype out /6 can go semi wild to gonzo..
Better than swapping EVERYTHING
After reading all of the comments all of you guys have posted, I agree now with XfbodyX and 8T2TOP and others above. Beefing up the /6 seems to be the way to go. ;)
So... what I would like OY to be is a CRUISER, not a racer. But I want more power - basically like what a stock V8 would provide. The stock 41 year old /6 just doesn't have the pickup that I would like, even though it's a Super Six and only has about 30K on it. I also want something that will play well with the existing A833OD transmission. I will likely have to have the work done due to lack of expertise, time, and space, so $$ is also a major consideration. :eek: OY is currently completely stock, has PS, PB, and no A/C.
With all this in mind, what would people suggest are the best modifications to make? What would give me the most bang for my buck? I'm sure that people will have different ideas on this, but I welcome everyone's opinion! :) Thanks in advance!
 

Camtron

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More gear, like a 210in/218exh Cam grind, swinger intake, headers/duel exhaust, nice little Holley street avenger and send it.
 
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AJ/FormS

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Everything you do to it with bolt-ons, with a possible exception of more carburetion, is gonna steal low-rpm power to make high-rpm power, that's just the way it works.
The formula is (Torque times rpm) divided by 5250 equals horsepower.
Suppose at 2400 your slanty is making 70 ftlbs; this is 32hp
Suppose your engine makes 113ft lbs at 2700rpm; this is 58 hp
Suppose at 3600 it is still making 113 ftlbs; this is now 77hp
bur suppose your slanty chokes there and by 4000 the torque has fallen to 66#, then the hp is 50 big ones.
This is a typical RWHP for your slanty,with the lame-O factory timing. By getting the timing right, you might be able to boost the ftlbs 10 to 15 % throughout the rpm range.So lets work off the assumption that you got the timing bugged out. So now the numbers look like;
35hp@2400;74hp@3000;98@3800 RWHP


If you put a bigger cam in it; you might lose 10% at 2400 to get 10% at 3800. So you trade away 3.5hp at 2400 and have 31.5 left . You lost it, it's gone, and it will take 10% more rear gear to get it to feel the same as it was before the cam swap. But the good news is plus maybe 15% at 3800 is now 113hp
Sounds good right?
But not if you have 2.45 gears in that yellow sweetheart...... 2400rpm is 26mph, and yur down 10% on power there, while 3800 in first gear is 40mph. Then when you shift, the Rs fall to 2360rpm, and yur back at 31.5hp, and yur goose is cooked cuz at 40 mph this is depressingly low, on account of that is probably just North of what it takes to maintain speed never mind accelerate. So the 2.45s gotta go.

But suppose you have 3.23s. then 3800 in first will be 31 mph, and on the 1-2 shift the Rs fall to 2361 again, you can't change that because that is in the trans. But now at 2361 your 31.5hp can accelerate the car .... because wind-resistance is still pretty low at 31 compared to 40 mph, and the power is gonna steadily increase to 3600 at 47mph. And then comes the shift into third, the Rs drop to 2770, and the power is back in the basement at about 64hp, and again just a tic higher than what it takes to cruise at, never mind accelerate. So the 3.23s gotta go

But suppose you take advantage of the overdrive and stick 4.10s in there. These will cruise at 65=2400 in od. Ok now 3800 in first will be 24 mph and yur at full power, say 113hp. On the 1-2 shift the Rs fall to 2361 same as before; but now you're at 24 mph and power will be rapidly building up again, and peaking at 3800=39mph. At the 2-3 shift, the Rs will again fall to 2771, now at 39 mph and 64 hp. Now yur car has to pull this to 65= 3300 which is near full torque so about 82hp. So accelerating at last !
But as you can see, at every shift, the Rs fall very low, right into the zone where the big cam lost power. And the extra power at 3800 didn't help much until you dropped the 4.10s in there.
So my thinking is this, if you stay normally-aspirated, you gotta have some gears anyway ....... so you might as well start with them. cuz 12hp, by itself, at 3800 is not gonna amount to much performance gain. And if you want more power than this, you'll need a yet bigger cam, and now you gotta bring the compression along, or the bottom end gets even mushier. You don't have a convertor to help with this.
Of course that tiny carb is gonna have to go, and a header will be a must and a new exhaust system,yada,yada,yada. So what starts out as a simple cam swap, ends with $3000 to $3500 spent, and then you still gotta get gears. Oy-vey.

For that kindof money, you couldda had a side-winder super-charger, or maybe a turbo.. And those air-pumps,increase the low rpm power like nothing else can .............. so whatever rear gears are in it now, can stay, at least until they blow up.

Ok so; that Magnum in the corner is looking mighty attractive about now.
I think; bang-for-your-buck, a healthy Magnum is the best choice. If you lived next door to me; we'd be done by now,lol.
Then maybe you'd let me drive it now and then; but you can't come unless you put a 5-point harness on your side,and wear a collar,cuz I'll be DRIVING it. We're gonna see what breaks first, fix it, and then DRIVE it some more. When it don't break no more, then you can DRIVE it.
We could be having so much fun. :):(:):)o_O:);):):cool::oops::cool::cool::):):):):):)
 
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Camtron

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Yea, long runner intakes totally rob the bottom end, a cam grind that will improve power from 1,400-4,600rpm is gonna hurt your bottom end, headers and exhaust are going to hurt your bottom end
 
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barbee6043

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Like AJ says, TORQUE.
Back in the 80's and 90's I must have drug home dozens of 68-9 runners an bees. I hated the 383 auto 3:23 ones but loved the 383 3:55 or 3.91 geared 4 speed ones! I would get it going and that 0 to about 50 or 60 was where I was at. Torque.
 

BudW

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I hated the 383 auto 3:23 ones, but loved the 383 3:55 or 3.91 geared 4 speed ones!
Well said. Even automatic with 3.91's are quite fun to drive.

I do recommend checking existing gear ratio first, then change accordingly - then sit back and get your opinion as to where to go from there. Gear ratio changes should come first, no matter where you end up going.


Back to the original question. If 50 people reply, you will get 50 different answers.
My opinion, the most cost effective for largest power per buck would be a 318/360 Magnum with the least fabrication needed. Also parts availability might be better on the Magnum. The job might even only take a weekend (or less) if you had the parts on hand, first.

I'd love to install a Gen III Hemi into an FMJ - but I just can't justify the cost to do so. At least prices are better now than it was say 10 years ago.
I've even played with the idea of finding a newer Caravan and transplanting the engine and electronics over to FMJ. Get ABS, Anti-Skid, Nav, backup camera, blind spot detection, rain sensors, and list goes on - but boy, that would require a ton of fabrication - and I just don't see that happening.

It comes down to: how much more power you want, how much $ you want to spend, do you want car to look like it originally came from factory that way, or do you want the "performance look" (whatever that is).
In my case, I want my big block(s) to look like just another 318 2-bbl car when I open the hood (even keeping the Lean Burn computer in place (not functionable) - but that is my goal. Only you know what your goal(s) are.
What we can do is help you with our experience once a direction has been set.
BudW
 
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