Question for those that swapped a big block into their A body.
- Thread starter dart_68
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I just took B body headers off my low block 69 cuda with manual steering. They will fit with but with lots of dings and dents. I just installed TTi 1 3/4 headers and they clear everything, big difference.
DrCharles
Well-Known Member
I did far less dinging and denting than that, partially because I cut the steering column jacket back to the firewall, and used a Flaming River U-joint instead of the pot-coupler. See the BBD tech pages for pictures (I bought the set from the guy who used them in those pics).
You also need the right mini-starter which eliminates another ding.
You also need the right mini-starter which eliminates another ding.
mopar65
Well-Known Member
There are some wicked runing small blocks out there. But my 73 dart swinger that weighed 3520 with me in it, ran 10.62 at 126 in the 1/4 on 93 pump gas. I had a 0.030 over 440 with about 10.9 compression. Installing 2 750 Holley DP and letting my friend drive it. He weighs about 100 pounds lighter than me at the time. The car ran a bunch of 10.49 in the 1/4. So I'm saying this you can run pretty fast on pump gas now daysSo given a 450 - 500 hp engine, would a big block be more economical to build than a 360 at the same hp? Would the BB run better on pump gas? Apologies to the OP if I this is straying too far off your question.
famous bob
mopar misfit
Out of curiosity, what gears and tires were on it at the time ?
mopar65
Well-Known Member
I had 4.10 in it but blew them up on the 4th pass. So I installed a set of 4:30 I had laying around. The tires were M/T ET Street Drag Radials in 275/60/15. I think the car would of been faster with the 4.10 but I never got around to trying a set again. Also my dart had the wrong stall at the time. I had a 9.5 inch converter that only stalled around 4200, the car should of had a 5200 stall converter. Which latter on I added, but never got to race the car before I sold it. Also my car was 100 percent street able
famous bob
mopar misfit
cool !
Dcuda69
Well-Known Member
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I have a stroked 400(470) in my 69 B'cuda with a 4spd and man steering. The headers and z-shaft are the tough spot. I use CPPA headers(old and much like TTI)with a stock BB k-frame and mounts. It all fits but it's tight and you won't be happy if you need to replace the starter...lol. I run an 8 1/4 with 3:73s. It's a street toy so it works just fine..if I put sticky tires on it,it might not. I run 73-up disc brakes in frt.,drums rear. I fabbed some frame connectors and put Hellwig sway bars front and rear. The car handles just fine....it goes straight when being hammered on and handles corners with ease. Healthy BB in A bodies are a blast. Most times I run out of road long before that stroker runs out of pull!!!
684door
Well-Known Member
I did the big block swap two years ago. I used the conversion mounts from small block to big block. I know every k frame is a bit different due to the factory assembly but I gotta say that I was not very impressed with how the mounts fit. I bought the shims, but getting the motor straight and level was a chore. I bought a factory big block k frame I may change to later. The 1 3/4 tti headers fit ok, but you have to install them with steering column out as well as torsion bars removed and even then the drivers side is avtight fit. The biggest issue involved the 4 speed swap. The headers run very close to the z bar. As noted by another member, starter install is a trick in itself. I had to put a DEI wrap on mine to avoid hot start issues. Don't get me wrong, my car gets a ton more looks with a big block 4 speed, but a small block would have saved me a ton of headaches.
SLOPAR72
Well-Known Member
I am beginning the process now going to a RB. Everyone will have their own reasons or loss or gains in the pocket book to make it happen and for me it was a wash really. In fact, once the car is running and I liquidate all my small block stuff the entire deal may cost around 2k and that includes a fresh drivetrain.
The Cylinder heads for the SB is pretty discouraging. I say that with a grain of salt because in the right hands anything can be made to work. For me and what I wanted the math just wasn't there and it's a fun project to work on. But with a BB I should be able to have a user friendly motor, decent track times, and drive the car when I want and where I want without hesitation.....
But I could be all wrong which is why the original drivetrain will go in the corner and anything I do with this conversion can be reversed in a New York minute... Having owned a streetable big block car with a nice time slip all I can say is things didn't seem to difficult with the cubic inches lol...
JW
The Cylinder heads for the SB is pretty discouraging. I say that with a grain of salt because in the right hands anything can be made to work. For me and what I wanted the math just wasn't there and it's a fun project to work on. But with a BB I should be able to have a user friendly motor, decent track times, and drive the car when I want and where I want without hesitation.....
But I could be all wrong which is why the original drivetrain will go in the corner and anything I do with this conversion can be reversed in a New York minute... Having owned a streetable big block car with a nice time slip all I can say is things didn't seem to difficult with the cubic inches lol...
JW
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Penstarpurist
Well-Known Member
As I'm sure it's been said before, no replacement for displacement! Lol, I think for our big block swap into a 1973 plymouth duster was of course cost. Not because of it being a bb cost to build an engine vs a sb cost to build. Though, big block parts are a bit more. It's when you get into bigger torsion bars, leaf springs, rearend, disc brakes, exhaust headers or even c body manifolds. B8g block c body oil pan has to be specific, aluminum radiator, etc. Subframe connectors, rollcage, etc. I know on any build or swap there are a million little things that nickel and dime the budget. But on a bb build there are several upfront costs that are alot more then nickels and dimes. The engine is the easy straight forward part, it's all the stuff that has to change or go with it to make it both safe function. That said, we would do it all over again.
Vamisk
Well-Known Member
I've got a 383 I want to throw in my Duster. It has factory electronic ignition for a slant six. Will that be able to function on a 383 or am I better off just using points for now?
dart_68
Well-Known Member
It should have no problem firing the 383...it doesn't know how many cylinders or cubes the engine has. The trigger to fire comes from the distributor.
Vamisk
Well-Known Member
Alrighty thanks for the info. Guess I need a new distributor then!
Yes, each engine family can only use certain parts from its own family. In your case, you NEED a B block distributor from a B series engine.
350, 361, 383, 400.
RB block distributors can be used if you can find the spacer to take up the room due to the height difference.
350, 361, 383, 400.
RB block distributors can be used if you can find the spacer to take up the room due to the height difference.
RPMagoo
Just An Old Motorhead
I had a 440 in a 68 Dart. -- (1) I cut a hole, with a hole saw, in the inner fender. to gain easy access to the #7 spark plug. -- (2) Torsion bars run thru TTI headers. -- Neither was a big deal.
SLOPAR72
Well-Known Member
I see you are running a motor plate. There is a Hemi Dart running in a local street car shootout we have in Richmond and I didn't want to bother him last night as he was dealing with chassis issues but he has motor plates also and it did not look like the K Member was notched for the oil pump and he had quite a bit of space. Why did you go with Motor Plates?
JW
RPMagoo
Just An Old Motorhead
-- The motor was in another car, that I bought, and it was set-up that way. - It was a 440 stroker.
mopar65
Well-Known Member
The TTI headers I used the Torsion bars did not go through them
dart_68
Well-Known Member
For right now I'm leaning towards a small block. A small block will let me get my Duster on the road cheaper and faster...but maybe a bit slower.
I'm still contemplating a killer 512 in the future.
inkjunkie
Well-Known Member
If folks would step out of the 70's they would realize that there IS indeed a replacement for displacement...
dart_68
Well-Known Member
Turbos are great but the cost and effort of setting them up is sometimes astonishing.
I agree. But that is the way to go for some big upper end numbers. Even anbelt driven supercharger is good. The snail housing units are very similar to a turbo charger and the roots 6-71, 8-71 add monsterous torque.
DrCharles
Well-Known Member
Centrifugal superchargers ("snail housing" ) tend to be "peaky" because the boost is proportional to the square of the impeller rpm.
Roots blowers are linear but are very heavy, inefficient at high boost levels (sometimes 50% or less) and don't work well with intercooling, and their sheer size can interfere with the driver's line of sight.
Turbos are the best compromise but can be a plumber's nightmare...
Pick your poison.
Sometimes it's just easier to build more displacement.
) tend to be "peaky" because the boost is proportional to the square of the impeller rpm. Roots blowers are linear but are very heavy, inefficient at high boost levels (sometimes 50% or less) and don't work well with intercooling, and their sheer size can interfere with the driver's line of sight.
Turbos are the best compromise but can be a plumber's nightmare...
Pick your poison.
Sometimes it's just easier to build more displacement.
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