Big Block Swap

-
Here are a couple of myths I debunked when I was mocking mine up.... And I was doing a 512 RB motor.

Heater motor- It cleared even with a set of cast MT Valvecovers.
Powerbrakes- I have Hrdroboost which is very small and was easily able to remove the Drivers side VC.

I recently sold my setup (mounts, headers, etc.) to a young kid that sounds similar to you. The real headache as I explained it to him is the rear steering setup. It just takes all your good real estate needed. But nothing jumped out as an impossible task. My biggest hurdle was I wanted power steering with full length Chassis headers and I figured it out but at a cost. The only other limitation you will run into is if you want to run a flat hood and a single plane intake.

But your young so go for it. The water's fine so jump in. For those that want to bash your efforts, either they don't realize your the next generation or they have never been around a well seasoned and well tuned BB car. Nothing like it....

JW
 
For the record, I was not hating on the OP for wanting a big block in his ride. Just stiring the pot. I’ve always said “to each, their own”. Most of the time when you see a big block A body, it’s at the drag strip 1/4 mile at a time. So it boils down to what you want out of a car when building it..
 
Here are a couple of myths I debunked when I was mocking mine up.... And I was doing a 512 RB motor.

Heater motor- It cleared even with a set of cast MT Valvecovers.
Powerbrakes- I have Hrdroboost which is very small and was easily able to remove the Drivers side VC.

I recently sold my setup (mounts, headers, etc.) to a young kid that sounds similar to you. The real headache as I explained it to him is the rear steering setup. It just takes all your good real estate needed. But nothing jumped out as an impossible task. My biggest hurdle was I wanted power steering with full length Chassis headers and I figured it out but at a cost. The only other limitation you will run into is if you want to run a flat hood and a single plane intake.

But your young so go for it. The water's fine so jump in. For those that want to bash your efforts, either they don't realize your the next generation or they have never been around a well seasoned and well tuned BB car. Nothing like it....

JW
How did you resolve the long tube headers and power steering issue?
 
To the OP.

Go for the big block and cross off the items on the list.

When i built my 67 dart i had a 440 block and a 340 block. I debated for awhile but i had the majority of the sb items i needed, plus the 340 was rebuilt. (20kms later it spun a rod bearing)
I stroked the 340 and running w5 heads now.

Hindsight i should of went 440.
Now i am collecting parts for a 400 stroker build for the 67 dart. So i have come full circle.
 
If you have the exhaust manifolds on your 383 auto combo that would work you could get your swap done at a reasonable cost. A few non factory big block a body ones that would work. When you take the k frame out to modify it install the larger torsion bars. Do not rush the job. As that could get frustrating. Not many 1976 a body's with 383s. With the torsion bars even small block is tight in that area. Regardless of engine exhaust is a cost hurdle for us Mopar guys.
The guys that have it made are the ones with strong preference of one engine over the other. I debated pros and cons of 6.4, small block and big block. I decided to go from 340 to 451. Good luck. Alot of info on this site.
 
Speaking of torsion bars... one reason the big-block gets a bad rep for handling is that the factory .89" bars are not nearly big enough. It will "wallow" unless you also add super-stiff shocks, then you'll hate the ride.
PST makes an affordable 1.03" bar (with discount for FABO members!) and it's amazing how much better my big-block A-body feels. Firm but not harsh ride. Don't let the size scare you off.
 
Speaking of torsion bars... one reason the big-block gets a bad rep for handling is that the factory .89" bars are not nearly big enough. It will "wallow" unless you also add super-stiff shocks, then you'll hate the ride.
PST makes an affordable 1.03" bar (with discount for FABO members!) and it's amazing how much better my big-block A-body feels. Firm but not harsh ride. Don't let the size scare you off.

Add aluminum heads, intake and water pump and your at small block weight again. Why change torsion bars?
 
Speaking of torsion bars... one reason the big-block gets a bad rep for handling is that the factory .89" bars are not nearly big enough. It will "wallow" unless you also add super-stiff shocks, then you'll hate the ride.
PST makes an affordable 1.03" bar (with discount for FABO members!) and it's amazing how much better my big-block A-body feels. Firm but not harsh ride. Don't let the size scare you off.

Big block cars get a bad rep, because people cobble them together, or want a drag race car. Factory cars handled fine the way they were set up. No special parts required.
 
Oh, they handled "fine"... by '60's standards, on skinny bias-ply tires... lots of room for improvement!

Back in the 80's I had a '70 A-body I converted from 318/auto to a slightly warmed 383 (iron heads, DP-4B intake, Holley 750 vac sec) and 4-speed. As mentioned, that didn't weigh much more than the 318. So I kept those t-bars and was never happy with the way the front end felt. Eventually I obtained a pair of factory .89 and it helped but not that much.

There is plenty of info on the FABO suspension forum about improved handling with the 1.03 bars. Check it out :)
 
FirmFeel has up to 1.12 t bars listed. Not sure of the others. I went with 1.00 bar with the large sway bar when I did my front rebuild over .89 bars and no sway bar. It was a night and day change for the better wth my 340.
 
Add aluminum heads, intake and water pump and your at small block weight again. Why change torsion bars?

Yep.

And do that with your small block and you're in slant 6 territory. And do that with your slant 6..... ugh.


Side note, was it Schumacher that had the Tri-y headers for big block A bodies that fit?
 
I recommend a crossmember modified for the big block. It will make it easier in the long run.
 
Oh, they handled "fine"... by '60's standards, on skinny bias-ply tires... lots of room for improvement!

Back in the 80's I had a '70 A-body I converted from 318/auto to a slightly warmed 383 (iron heads, DP-4B intake, Holley 750 vac sec) and 4-speed. As mentioned, that didn't weigh much more than the 318. So I kept those t-bars and was never happy with the way the front end felt. Eventually I obtained a pair of factory .89 and it helped but not that much.

There is plenty of info on the FABO suspension forum about improved handling with the 1.03 bars. Check it out :)

Still handles fine. Never had skinny tires. Ran it as a daily driver for years, embarrassed a lot of cars.
 
383 is a great engine, don't let the meatheads deter you from your vision. I'm building a 440 for mine, but I like the 383 better because the piston speeds are lower and you can rev the snot out of a 383 without breaking it. I once build a 383 for a '74 Cuda I had that was fearsome and really fun, low budget too.
 
The only drawback with a 383 compared to a 400 or 440 is some after market head manufacturers like trickflow recommend their heads be used on 4.32 or larger bore diameter. One advantage of a big block is you can make 600+ horsepower more easily with a lower compression and run pump gas.
Don’t be deterred is not that hard to do.
D2236CB4-FEA2-4D6B-A585-B10320AFA4A5.jpeg
 
Who cares what you prefer this guy wants to put a 383 in his Duster.

The largest radiator for a small block will cool a 383 and a later waterpump housing will be needed to use the sb radiator.

At this time fabrication skills will get that big block installed faster because conversation mounts are hard to come up with. You will need kickdown linkage, carb brackets etc..

Hooker makes fender well headers for the Abody big block swap.

Yes a big block 727 is needed.

And an Abody 727 drive shaft is needed, original or fabricated.

If you can't fabricate yourself you will need to find someone who can.

This is not a weekend swap for a novice.
What do you mean "A body drive shaft"? Ive got a BB 727 from a B body that i was thinking of swapping into my 74dart with a fairly stock 383. What is the difference besides having to cut it down.
 
383 is a blast in a light car, and pretty much unbreakable if never run out of oil. But it isn't a drop in, as stated above. I'm putting a 440 in my '69 Dart and the headers alone were 1K. Mounts, different water pump housing, transmission and driveshaft, rear axle, it all adds up, plus you really need to tie the subframes with the torque of a big block. I have waffled many times, but since I already had all the parts for the swap that's what I am doing, and converting to 4 speed while I am at it. My narrowed Dodge Van Dana60 is waiting for a locker.
 
The only drawback with a 383 compared to a 400 or 440 is some after market head manufacturers like trickflow recommend their heads be used on 4.32 or larger bore diameter. One advantage of a big block is you can make 600+ horsepower more easily with a lower compression and run pump gas.
Don’t be deterred is not that hard to do.View attachment 1715776705

I went with Mazzolini Pro Parts step headers for mine, had them ceramic coated. Your install looks really good!
 
383 with manual steering, floor shift and straight plug heads can use Hedman B-body headers (78030) with small if any dings. That's what I have on my 451 (a little small, but would be perfect for a 383).
They cost new 25% of TTI, so if you need a small dimple, don't feel bad about breaking out the ball-peen hammer :)
 
-
Back
Top