The Elephant In The Room: unloading the load from a B-body.

[rmchrgr]

Mopar John, I actually learned a lot about 904s from DVW’s son Scott. Many years ago he wrote a very detailed reference post on Moparts explaining all the nuances of the different internal parts and how they work together. It was very helpful when I built mine. Click here to read it.

It sounds like your trans is a little more advanced than a basic street/strip build up but if you have an interest in learning some of the ins and outs of these things that post is a good place to start.

Eventually I’d like to rollerize my trans. I like to think that reducing friction is akin to weight reduction.

 

[Mopar John]

Mopar John, I actually learned a lot about 904s from DVW’s son Scott. Many years ago he wrote a very detailed reference post on Moparts explaining all the nuances of the different internal parts and how they work together. It was very helpful when I built mine. Click here to read it.

It sounds like your trans is a little more advanced than a basic street/strip build up but if you have an interest in learning some of the ins and outs of these things that post is a good place to start.

Eventually I’d like to rollerize my trans. I like to think that reducing friction is akin to weight reduction.

rmchrgr,
Thanks for the link!
I will take a look at it soon.
Every year when we look and freshen we try things mostly using stock parts.
There are more and more lightweight 904 parts coming out as this becomes more popular!
MJ

 

[Mopar John]

No Dave Smith from Pro-Trans stuff is a work of art. Most internal parts are billet aluminum, toringtons thruout, up to 6 pin planets, multiple gear ratios available. I repair/freshen them. The last one I did had stripped an input hub when it broke the Dana on launch. The part pictured us about 20 years old. Seen plenty of 850+hp passes
Doug

View attachment 1703706

Nice piece!
MJ

 

[rmchrgr]

rmchrgr,
Thanks for the link!
I will take a look at it soon.
Every year when we look and freshen we try things mostly using stock parts.
There are more and more lightweight 904 parts coming out as this becomes more popular!
MJ

You got it. Thank Scott and DVW for doing that though. The post has been archived for a long time now since it's almost 20 years old. It's still the only thorough reference out there for modifying 904s though so I'm glad it's still viewable. Just be aware that some of the part #s that got added in towards the end may no longer be available or have been superseded.

Several years ago I made a post of my own on FABO specifically about the 999 variants. To be clear, my post was only to show what the few application-specific parts inside look like. How to identify a 999 transmision.

Though I wasn't old enough to know, I have a feeling back in the '60s and '70s no one gave a rat's *** about 904s. There's a brief passage about them in the old Mopar Chassis bible so the factory engineers must have understood their benefits in milder race cars but I'd bet most of the time they got pulled and scrapped in favor of a 727.

 

[fullmetaljacket]

You got it. Thank Scott and DVW for doing that though. The post has been archived for a long time now since it's almost 20 years old. It's still the only thorough reference out there for modifying 904s though so I'm glad it's still viewable. Just be aware that some of the part #s that got added in towards the end may no longer be available or have been superseded.

Several years ago I made a post of my own on FABO specifically about the 999 variants. To be clear, my post was only to show what the few application-specific parts inside look like. How to identify a 999 transmision.

Though I wasn't old enough to know, I have a feeling back in the '60s and '70s no one gave a rat's *** about 904s. There's a brief passage about them in the old Mopar Chassis bible so the factory engineers must have understood their benefits in milder race cars but I'd bet most of the time they got pulled and scrapped in favor of a 727.

Some cop cars have the 999's.
Curt Sr. (TOP BOY) did some voodoo on my police package using 999 parts. I forgot what it was exactly, but it shifts and chirps like a champ.
I'm going to his place soon to bring him a 904 and an extra back up '65 pushbutton to work some of his magic using primarily stock parts. The right stock parts though. Though they are heavy compared to that billet aluminum jewel that Doug posted. Jealous.

 

[fullmetaljacket]

Some cop cars have the 999's.
Curt Sr. (TOP BOY) did some voodoo on my police package using 999 parts. I forgot what it was exactly, but it shifts and chirps like a champ.
I'm going to his place soon to bring him a 904 and an extra back up '65 pushbutton to work some of his magic using primarily stock parts. The right stock parts though. Though they are heavy compared to that billet aluminum jewel that Doug posted. Jealous.

On another note, I believe that MJ here has more patience than any or all of us with his usage of stock parts meticulously picked for service depending on their respective weights. Down to the smallest and last bolts. Love it.

 

[Mopar John]

So attached are a couple of transmission weight loss photos.
Once we learned that the 904 would live Keith started changing items one at a time.
In this case we went form a 4 pinion planetary to a 3 pinion planetary.
The results were 1 lb 14.9 oz down to 1 lb 11.5 oz or a loss of 3.4 oz of rotating weight!
MJ

 

[fullmetaljacket]

So attached are a couple of transmission weight loss photos.
Once we learned that the 904 would live Keith started changing items one at a time.
In this case we went form a 4 pinion planetary to a 3 pinion planetary.
The results were 1 lb 14.9 oz down to 1 lb 11.5 oz or a loss of 3.4 oz of rotating weight!
MJ

View attachment 1704199

View attachment 1704200

Those ounces lead up to great hole shots. Everything ends up going through the transmission, including weight.

 

[Mopar John]

So there is a lot to learn about transmissions and their rotating weight!
But now I would like to move onto the water pumps and housings.
My first weight loss was going from the cast iron housing and pump to aluminum parts using a Moroso pump motor.
The weight went from 14 pounds down to 7 pounds up front and the engine no longer driving the belt.
The total weight was down to 3034 now and heading toward 3000 lbs!
Later I went from this set up to a Meziere pump with housing.
This later change didn't result in a weight loss but has been a better set-up for cooling.
MJ

 

[fullmetaljacket]

So there is a lot to learn about transmissions and their rotating weight!
But now I would like to move onto the water pumps and housings.
My first weight loss was going from the cast iron housing and pump to aluminum parts using a Moroso pump motor.
The weight went from 14 pounds down to 7 pounds up front and the engine no longer driving the belt.
The total weight was down to 3034 now and heading toward 3000 lbs!
Later I went from this set up to a Meziere pump with housing.
This later change didn't result in a weight loss but has been a better set-up for cooling.
MJ

View attachment 1704728

View attachment 1704729

Are you running an aluminum thermostat neck housing?
I'm sure that chrome steel unit was heavy.

I also see that you're now running the GM alternator. Good insurance. My GM unit is a 100 amp bad boy and weighed a few pounds less than the original 35 amp Mopar unit.

Not trying to sound like a nag here, but I see a pound or so that can be removed on your setup just in bolts.
Ohh, and don't forget the titanium worm gear hose clamps available from McMasters. Let me shut up.

 

[Mopar John]

Lee,
The thermostat neck is aluminum!
Since you mentioned the alternator that was next up any way.
My first change was from a stock Mopar alternator to a mini alternator.
the weight savings was great from 14lbs down to 5lbs a savings of 9lbs!
But it couldn't keep up with the electric fan on.
So I went from the mini to a 100amp unit that you spotted.
That increased the weight from 5lbs up to 8lbs but still 6lbs less than the Mopar unit.
Nice aluminum low mount with short belt that doesn't jump off the pullies!
The weight was down to 3025 at the first alternator change!

Yes, I do need to get an assortment of titanium bolts some day!
Just recovering from an engine freshen up!

 

[HersheysHemi]

I haven't had time to read thru this whole thread.
I was wondering if anyone knows about what year fiberglass fenders would have first become available for a 1969 roadrunner?
I wasn't alive back then so I'm curious.

 

[fullmetaljacket]

I haven't had time to read thru this whole thread.
I was wondering if anyone knows about what year fiberglass fenders would have first become available for a 1969 roadrunner?
I wasn't alive back then so I'm curious.

There are many companies out there that fabricate fiberglass fenders for the popular '68-70' B-bodies such as your Road Runner, but there are also carbon fiber specimens that are even lighter and stronger.
As far as fiberglass quality pieces, unfortunately, the now defunct Stinger/AAR company was the by far the best out there. I saw the pieces myself and was highly impressed in spite that I love metals. If you can find any virgin Stinger/AAR pieces, you are in luck. They almost need nothing as far as prep work before mounting and painting.

That being said, MJ here has steel front fenders and I also have steel fenders. MJ's fenders are probably the lightest out there by sheer removal of undercoating, removal of deep coats of paint and unnecessary trim. Mine on the other hand are '65 thin gauge factory lightweight pieces which put them in a category of their own, so not a fair way to cut weight on a budget.
For a race car, chemical milling( Acid dipping) is another way of cutting weight on the fenders, but not budget minded either and delicate pieces to contend with.
If you get a chance, read through this long thread for some ideas that are cool. Pick your poison thereafter.

 

[HersheysHemi]

There are many companies out there that fabricate fiberglass fenders for the popular '68-70' B-bodies such as your Road Runner, but there are also carbon fiber specimens that are even lighter and stronger.
As far as fiberglass quality pieces, unfortunately, the now defunct Stinger/AAR company was the by far the best out there. I saw the pieces myself and was highly impressed in spite that I love metals. If you can find any virgin Stinger/AAR pieces, you are in luck. They almost need nothing as far as prep work before mounting and painting.

That being said, MJ here has steel front fenders and I also have steel fenders. MJ's fenders are probably the lightest out there by sheer removal of undercoating, removal of deep coats of paint and unnecessary trim. Mine on the other hand are '65 thin gauge factory lightweight pieces which put them in a category of their own, so not a fair way to cut weight on a budget.
For a race car, chemical milling( Acid dipping) is another way of cutting weight on the fenders, but not budget minded either and delicate pieces to contend with.
If you get a chance, read through this long thread for some ideas that are cool. Pick your poison thereafter.

Thanks for the reply. I was just curious when fiberglass fenders started making their first appearance in drag racing on production cars?
I have a 1969 hemi roadrunner that was a Plymouth dealership's drag car when new and it has fiberglass fenders on it.
I'm just curious if they existed in the early 1970's or didn't come out till early 1980's?

 

[fullmetaljacket]

Lee,
The thermostat neck is aluminum!
Since you mentioned the alternator that was next up any way.
My first change was from a stock Mopar alternator to a mini alternator.
the weight savings was great from 14lbs down to 5lbs a savings of 9lbs!
But it couldn't keep up with the electric fan on.
So I went from the mini to a 100amp unit that you spotted.
That increased the weight from 5lbs up to 8lbs but still 6lbs less than the Mopar unit.
Nice aluminum low mount with short belt that doesn't jump off the pullies!
The weight was down to 3025 at the first alternator change!

Yes, I do need to get an assortment of titanium bolts some day!
Just recovering from an engine freshen up!

View attachment 1704781

MJ. Yes, I almost sprung for the mini Mopar style alternator, but waited in the shadows to see what real world road manners it would present. Like you, I'm glad that I opted for the GM 100 amper and I never looked back. I did go for the blacked out unit like yours so that it could kind of disappear to the naked hawk eyes of fellow Moparites, but those hawk eyes are sharp. They blew my cover and never let me forget it. LOL.

 

[fourgearsavoy]

Thanks for the reply. I was just curious when fiberglass fenders started making their first appearance in drag racing on production cars?
I have a 1969 hemi roadrunner that was a Plymouth dealership's drag car when new and it has fiberglass fenders on it.
I'm just curious if they existed in the early 1970's or didn't come out till early 1980's?

There were a few companies making glass fenders back in the 60's and most of them were very thin custom jobs. There was a guy in the Cleveland area that owned a boat shop and he would make any part you wanted. So you get them in 69 if you wanted them.

 

[HersheysHemi]

There were a few companies making glass fenders back in the 60's and most of them were very thin custom jobs. There was a guy in the Cleveland area that owned a boat shop and he would make any part you wanted. So you get them in 69 if you wanted them.

Ok thanks. So it's possible they could be from the early days of the car.
I need to take closer at them and see if they have any sort of a name on them.
I appreciate your help.

 

[fullmetaljacket]

Thanks for the reply. I was just curious when fiberglass fenders started making their first appearance in drag racing on production cars?
I have a 1969 hemi roadrunner that was a Plymouth dealership's drag car when new and it has fiberglass fenders on it.
I'm just curious if they existed in the early 1970's or didn't come out till early 1980's?

If I remember correctly, Fiberglass plus was creating pieces in the mid 60's for the early B-cars and by the very early '70's, my friends factory 6ix barrel SuperBee had fiberglass fenders that were installed for street action. Believe it or not, the fenders were almost as heavy as the steel fenders themselves.
Today's fiberglass fenders are more refined and lighter. It all depends on what kind of car you are building. I would lighten the steel ones if it were me with that year car.
As far as weight, I've heard that the '68 RR's are the lightest, but the '69's are not far off. The '70 gets a little more porky and thus more challenging.
MJ? You've got the podium.

 

[fullmetaljacket]

Ok thanks. So it's possible they could be from the early days of the car.
I need to take closer at them and see if they have any sort of a name on them.
I appreciate your help.

A competitive dealership might have done what serious racers and street grudgers were doing and went with available fiber pieces at the time. If your glass fenders were dealer installed for drag competition, they may be Fiberglass Plus or VFN pieces. Nice history right there.

 

[HersheysHemi]

If I remember correctly, Fiberglass plus was creating pieces in the mid 60's for the early B-cars and by the very early '70's, my friends factory 6ix barrel SuperBee had fiberglass fenders that were installed for street action. Believe it or not, the fenders were almost as heavy as the steel fenders themselves.
Today's fiberglass fenders are more refined and lighter. It all depends on what kind of car you are building. I would lighten the steel ones if it were me with that year car.
As far as weight, I've heard that the '68 RR's are the lightest, but the '69's are not far off. The '70 gets a little more porky and thus more challenging.
MJ? You've got the podium.

I'm still debating what my long term plans are for the car.
I'm not sure if it should be restored factory stock or left as a drag car since that is what the dealership used it for.
I'm still trying to find more history on the car.
It was from the Long Island New York area when new.
The car is stuck in the 1970's.
It is on slotted mags wheels with the old drag slicks from back then still on it.
I would like to find a nice pair of original fenders for it.