Technical Ospho for headers or best exhaust for early Dart

I've pounded the crap out of a lot of small block Mopars (318- 360s) in A (and B) body Mopars. If you are not on the drag strip where 10ths of a second count (or heavy duty real street racing), headers are a waste of time and money!

Manifolds (even the 318 manifolds you had) with dual exhaust is all you need for street driving (I did a lot of street racing), they are good up to around 4500 rpm (above that, put an H pipe in the dual exhaust just after the trans crossmember). Above 5500 rpm, that small block better have some good stuff inside of it. Real life experience.

If you are seeking the best exhaust manifold for higher rpm performance, the Magnum motor exhaust manifolds have better flow then any other small block Mopar exhaust manifold (including the famed 340 TA 6 pack exhaust manifolds). Of them, the 93 Dakota truck (one year only) was the best, only because at the connection at the exhaust pipe, the manifold exhaust exit port was a 1/4" larger diameter (you better have a normal Magnum manifold to compare the opening to). I believe much of that improvement was because the original Y pipe (yes, single exhaust) was also a bit larger diameter at the manifold connections. The replacement Y pipes are all the same diameter and bolt onto the 93 manifolds. Read that as many times as it takes to understand that the very best flowing exhaust manifolds Mopar made for their small blocks were connected to a single exhaust system. The famed Dakota RT had single exhaust, and the legend Little Red Express trucks of the late 70s had (not great flowing) exhaust manifolds and dual exhaust.

I have never installed a magnum exhaust manifold into an early A body, I suspect it could be a challenge due to the rear pipe connection.

Change to the mini starter. Rid yourself of the old, heavy, large, gear reduction original.

 

Thanks Gene I have Dakota RT exhaust manifold, at present it doesn’t fit if you look at photos 1 and 2 it hits the column tube and the coupler. The tube I figure I could remove the shift lever and cut 3 or so inches off reinstall the bearing and seal. I will not grind on the coupling however I might be able to grind enough off the manifold for clearance. I’m not against mini starters but don’t want to spend money if not needed.
The manifold that came with the engine absolutely won’t fit it dumps right at the steering box.
I’ve been told and have read that the single exhaust works very well indeed. My sources tell me a min of 2-1/2” and up to 3” will handle any HP I ever intend to make.
Gene have you ever shortened a steering column tube? Can I simply cut 3” off remove the shift lever and reinstall the bearing and seal? I’m going to install a floor shifter so don’t need the column shifter. I wouldn’t even mind the column shifter although it would an absolute nightmare to make work.
Dan

 

Dan,
I owned and built stock bodied Mopar dirt track cars for years. I've probably done any modification to most any part of the car you can imagine, and probably many parts you can't imagine.
The steering column on your A body is a 3/4" two piece shaft with the "collapsible" section (I don't remember what year the collapsible was introduced, before that would have been a one piece shaft and non collapsible outer tube) carefully mounted inside the outer tube (with a collapsible section) with an upper bearing (or bushing) and a lower bearing (or bushing). Mopar used the outer tube to mount the column into the car, and to hold things like the turn signal switch and a bunch more stuff as the years added on.

On our dirt track cars, we eliminated the outer tube most of the time. The 3/4" shaft needs to be supported at the top of the shaft, and at the floor level. The 3/4" shaft can be shortened (or lengthened) as needed, there are companies that specialize in steering U joints and couplers and anything else needed to safely accomplish this task. Borgeson (I'm sure that is incorrectly spelled) was the 1st company creating the steering shaft parts and is likely the most expensive, Flaming River is another, there are several.

On a street driven ride, I would not eliminate the outer tube, but the bottom bearing can be relocated farther up inside of the tube and the excess tube can be cut off. There may be modifications that may need to be done so the bearing fits correctly into the tube (its been a long time since the A body cars, and there were a few changes through the years).

I don't know your skill level nor what equipment you have, and I understand tight budgets, but, the factory location of the bottom steering column mounting point can probably be modified by enlisting some of the steering shaft u joints and other parts. Moving the bottom of the steering column an inch or two may change the exhaust picture completely. That may require making a new bottom bearing mounting point on the floor and the addition of a couple U joints. Done correctly, the steering column shaft does not wobble as it turns, if it wobbles, its not correct and needs to be corrected. I need to warn you that the rubber piece sandwiched into your steering column joint is NOT intended to be used as a U joint, it is simply to reduce vibrations in the steering column. If its used as a U joint, it may fail pretty quickly, and then you loose the steering.

I have relocated the bottom steering column mounting point on several street driven vehicles (including both of my current modified street driven vehicles). On your early A body, you may have to modify the upper column mount so the shaft angle can change a bit, as needed. The newer A body upper column mounts have some factory built in angle adjust ability.
I like to see at least 1/4" of clearance all around the entire length of steering shaft rotating components at all times, as the shaft rotates.

With specific pictures and questions concerning your car, I can help guide you if you wish to venture into the bottom mount relocation. Just remember, my knowledge exists from years of experience dating back into the early 1970s, it just has to be aligned with what you are dealing with now.

 

Thanks Gene,
I’ll get out in the shop later today. I’ll get better pictures of the tube, shift lever and coupling. I sure would appreciate guidance on my project. Mopars are new to me and am learning as I go. I have fair to good fabrication skills and I’m not afraid to tackle almost anything. I do like to know the pros and cons of my modifications especially anything in regards to safety. That is Steering, Suspension and braking I definitely want right.
Dan

 

If the plan is to make a set next year, to match what you want to make fit.
Why not modify them as-is, run them and just keep the hood down for the time being.

 

@gene-koning @RodStRace
The engine mount is about 3/4” up on drivers side. If I cut the column tube back at the yellow mark that will clear. If I replace the coupling (marked X) with a u joint that has a OD of 1.225 I think it will clear. The coupling is 2” at the widest point and 1.375 at the narrowest point. I can’t move the steering column at the dash without cutting up the dash which I don’t want to do.I could maybe move the column 1/4” at the floor. I will remove the steering shaft and column set the engine all the way down and take Some measurements . I know where the shaft sits so I’ll know if using a u joint will give me the needed clearance. thank you for the help.
Dan

 

The fourth picture, if you did a floor shift, you could cut the outer housing at, or even above the floor pan and move the bottom bearing up to that point. You will probably have to cut the steering column above the shift lever on the shaft. With the steering shaft in the column cut, you can install a weld on, or pinned U joint (with column end being round 3/4", or whatever your shaft measures) onto the shaft at the bottom of the freshly cut column. Point the steering shaft towards the left side inner fender (you will probably need to buy a short piece of Double "D" (DD) steering shaft and another U joint), you can buy U joints with one or both ends DD, and something different on the other end of the U joint). A steering shaft bearing mount for the extra shaft might be a needed item to stabilize the short shaft. Then you should be able to connect the end of the DD shaft to another U joint, to replace the piece on the steering box. That piece is held in place by a hollow pin, drive it out, pry the coupler off the steering box, get a spline count and diameter for the short shaft out of the steering box. The U joint for that place will have one side to match the size and spline count of the steering box shaft, and the other side of the U joint will have the DD end on it. You will likely be able to move the steering shaft out of the way to clear the manifold, the limiting factors will be the angles the U joints can operate within. With 3 joints, a shaft bearing mount, and a 12" length of DD shaft, it is not a cheep modification, but less then a set of headers.
Kind of like what this fine art work shows....
You can cut up a 3/4" round wood dowel from a lumber company to see how much clearance you can get before you cut anything up.

You may be able to improve the U joint angles if you can shim two of the 3 bolts holding the steering box in place with a washer or two between the box and the K member. An 1/8" change at the K member makes a pretty big difference 8" away from where the steering column connects.

It does look pretty tight at the dash piece. Modifying the bracket to lower the column might gain you a bit of angle change, but that would also lower the steering wheel in the car. If I remember correctly, the steering wheel sits pretty low to begin with.
I think you should be able to gain what you need with the bottom end of the column.

 

Thanks Gene, I’m going to pull the steering column and cut the tube and go from there. I can’t get the coupling to budge from the steering box. My son will help me later tonight or tomorrow. We have some very good farm and ranch stores that may have the needed u joints and D shafting I’ll look tomorrow.
Thanks again
Dan

 

Good question but no because a couple spots on cylinders 1 & 7 flange is only 1/4” and removing would make an awfully narrow sealing surface. I’ve thought about making a taper shim to place between the manifold and head but that would require spot facing the bolt area. Machine shop rates would make it pricey to make the tapered shim and spot facing. Dang I retired to early, sure miss the machine shop. My photo sucks but it shows the thickness 7-3/4 to 8
Dumb question can I use a straight coupling / basically a piece of tubing instead of a u joint if everything is lined up in other words in a perfectly straight line?
Thanks
Dan

 

Borgeson shows a bunch of them.

 

Actually my shim drawing is bass ackwards the thick side should be on top
Dan

 

Edited drawing
Dan

 

Thanks I’ll get on their site and look around.
Dan

 

Great that @gene-koning can spell out the needed info.
The thing I wish to add is only that you did right with lighting and capturing the parts.
Thank You

 

I Ospho headers, then after they set overnight, I cook them with my torch. Makes it where the paint don’t pop off first time it warms up.

 

Indeed, the very clear pictures made it easy to grasp what the challenges are.

The shaft that comes out of the steering box has splines. You can use a straight coupling if it has the correct splines to mate with the steering box. I'm not sure coming straight off the steering box is going to help you much, unless you can shift the angle at which the steering box is bolted to the K member.

Those couplings on the steering box don't like to come off easily. Make sure the end of the shaft is really clean, and the whole thing is well lubed. Then, its still a battle, be careful about wedging things between the coupler and the end of the box where the shaft passes through.

 

After you cook the headers with your torch, do they still give a nasty smell when they get hot again? My main concern is with toxic fumes in a confined area. Under the hood of that early A body Mopar is very small.

 

I removed the steering shaft and column with my son Nics’s help it was a bear. Sprayed it down with Kroil yesterday and again today. We used a piece of 3/8 plate against the steering box and a BFPB once in started moving it went fairly easy. I have the engine shimmed up 3/8” on drivers side and pushed as far to passenger side as the mounts allowed. Tomorrow I’ll install the transmission and reinstall the eng/trans to make sure it will work.
The nub on the manifold is deceiving it’s about an inch and a half above the steering shaft. Really wish that was where the interference was as I could grind it off.
Dan

 

I’ll also investigate the steering box mount, maybe I can tilt down and then assemble per your drawing @gene-koning .
Dan