70 Duster BB swap Info

[outlet1265]

I pulled a 318/904 out of a 70 Duster, going back with a 383/A833 4-speed. Will the transmission mount line up at the cross member or will I need to modify something?
Will the headers clear between the inner fenders without cutting anything?
Thank you, any other tips would be greatly appreciated.

 

[mygasser]

i can't confirm on the big block but if it helps i swapped from auto to 4 speed in my 68 valiant and the mount sat right back on the stock crossmember. also if you haven't done it yet then consider bolting the 4 speed hump in place. it means you can fit the shifter and rods from in the car where it's easy to access. again i did this on my valiant, i used nutserts/rivnuts to make final assembly easy.
neil.

 

[outlet1265]

Thank you, I love that idea, I will definitely try that. This was a manual transmission car that someone converted to an automatic, so the hump was changed, bolt in would definitely make good sense.

 

[Professor Fate]

I pulled a 318/904 out of a 70 Duster, going back with a 383/A833 4-speed. Will the transmission mount line up at the cross member or will I need to modify something?
Will the headers clear between the inner fenders without cutting anything?
Thank you, any other tips would be greatly appreciated.

Transmission mount will be fine, but the tunnel does need to be modified to clear the linkage (you probably know that, but just sayin').
Header clearance is unknown, since you didn't say what headers you are using... that said, I've yet to see any headers (esp. big block) that didn't require at least a little massaging to fit nice.

 

[outlet1265]

Thank you, any suggestions on headers?

 

[mygasser]

a couple of pics

 

[mygasser]

i briefly had a 383/727 sat in my valiant (don't ask, lol) and schumaker headers cleared, even with the power steering box it had at the time.
neil.

 

[Professor Fate]

Thank you, any suggestions on headers?

All the usual suspects- Doug's, Tti, possibly Schumacher. Plus here are some interesting alternatives:
Tech Index

 

[outlet1265]

All the usual suspects- Doug's, Tti, possibly Schumacher. Plus here are some interesting alternatives:
Tech Index

Good info, Thanks

 

[outlet1265]

a couple of pics

View attachment 1716407089
View attachment 1716407090

I love how you did that, I will definitely copy your idea, thanks again

 

[Muswagon]

Laying the hump over the tunnel it will sit exactly where it naturally wants to, and you outline the outside, cut an inch or more inside. There is an episode of roadkill garage with the flat red duster they cut this hole. I can't stand Frieberger but Steve is awesome to watch and listen to

Schumacher headers if you want great clearance with zero issues. Tons of room with my 440, you will have more

Schumacher mounts on your biscuit style (if you have not changed) k member, very easy install relatively speaking

Believe your driveshaft will be correct length but you will need a different slip yoke for A833

BB rad

 

[outlet1265]

Laying the hump over the tunnel it will sit exactly where it naturally wants to, and you outline the outside, cut an inch or more inside. There is an episode of roadkill garage with the flat red duster they cut this hole. I can't stand Frieberger but Steve is awesome to watch and listen to

Schumacher headers if you want great clearance with zero issues. Tons of room with my 440, you will have more

Schumacher mounts on your biscuit style (if you have not changed) k member, very easy install relatively speaking

Believe your driveshaft will be correct length but you will need a different slip yoke for A833

BB rad

Thanks for the good information!

 

[AbodyBB]

So I hope I can help with a few pointers.
3 speed and 4 speed manual along with 904 had the same tail shaft length. 727
all had long tail shaft so they required a shorter driveshaft.
Early 4 speeds 67 used the “small” slip yoke 26 spline if I remember right. Earlier (65 and older) transmissions used a flanged output. Later 4 speeds (68 and newer) and 727 used the 32 spline slip yoke.
If your car is a 7 1/4 then you must
Upgrade to the 8 3/4. That will also change the length of your driveshaft.

So in short you will need to swap slip yokes at the least. At most a whole new driveshaft to bolt to a new axle.

Exhaust has been the hardest challenge on BB A body swaps. Schumacher Creative industries headers do fit really well but require to use of the newer starter motor. Those headers also require a modified clutch shaft and header pipe to work with a manual trans. I don’t think either are available new any more.
TTI headers also require a modified torque shaft and header pipe for the clutch. I believe they are available but they are expensive.
Your best option now is actually a hydraulic clutch. All headers can then be used.

Finally engine mounts will determine trans placement. Swap type mounts for that application (Schumacher again) require that the driver side mount tower be notched for the oil pump.
Later spool type k-frame can be modified to use the c-body mount and not have as much clearance issue. They need some clearance on the drivers side tower for the pump as well as some block/pan clearance on the steering gear mount. Lastly you can hunt down an original BB k-frame and mounts and find the block to match. For a 383 the block isn’t hard to find. A 66 and earlier will have the bosses cast into the block.
All those methods put the engine very close to factory location so the trans mount bolts to the cross member in the stock location.
Hope I didn’t complicate things. Mounting a B or RB in an A body is a really tight fit but great fun. Do the research like you are.
Don’t forget the go also needs to stop so make sure your brakes are to task.

 

[oldkimmer]

Also it matters if u have an A body tranny or a B,C,E or F body tranny. Or a truck tranny. U didn’t give us very much information to go on.

 

[outlet1265]

So I hope I can help with a few pointers.
3 speed and 4 speed manual along with 904 had the same tail shaft length. 727
all had long tail shaft so they required a shorter driveshaft.
Early 4 speeds 67 used the “small” slip yoke 26 spline if I remember right. Earlier (65 and older) transmissions used a flanged output. Later 4 speeds (68 and newer) and 727 used the 32 spline slip yoke.
If your car is a 7 1/4 then you must
Upgrade to the 8 3/4. That will also change the length of your driveshaft.

So in short you will need to swap slip yokes at the least. At most a whole new driveshaft to bolt to a new axle.

Exhaust has been the hardest challenge on BB A body swaps. Schumacher Creative industries headers do fit really well but require to use of the newer starter motor. Those headers also require a modified clutch shaft and header pipe to work with a manual trans. I don’t think either are available new any more.
TTI headers also require a modified torque shaft and header pipe for the clutch. I believe they are available but they are expensive.
Your best option now is actually a hydraulic clutch. All headers can then be used.

Finally engine mounts will determine trans placement. Swap type mounts for that application (Schumacher again) require that the driver side mount tower be notched for the oil pump.
Later spool type k-frame can be modified to use the c-body mount and not have as much clearance issue. They need some clearance on the drivers side tower for the pump as well as some block/pan clearance on the steering gear mount. Lastly you can hunt down an original BB k-frame and mounts and find the block to match. For a 383 the block isn’t hard to find. A 66 and earlier will have the bosses cast into the block.
All those methods put the engine very close to factory location so the trans mount bolts to the cross member in the stock location.
Hope I didn’t complicate things. Mounting a B or RB in an A body is a really tight fit but great fun. Do the research like you are.
Don’t forget the go also needs to stop so make sure your brakes are to task.

Wow, a lot of great information there, I've done several B&E body swaps no issues at all, this definitely seems a little more involved. Thank you for taking the time to help a brother out!

 

[outlet1265]

Also it matters if u have an A body tranny or a B,C,E or F body tranny. Or a truck tranny. U didn’t give us very much information to go on.

The trans I have is out of a B body, so I know I would need a different tail shaft housing. I am open to source something that fits better. The bell housing is aftermarket and I believe will accept a few different options, I guess I'll need to dig a little deeper.

 

[Muswagon]

Cannot miss a chance to plug the Malwood hydraulic system. 440 with A833 and Schumacher headers. No clearance issues anywhere including the Borgeson PS pump I added later. Everything is super tight but it all fits together

 

[Swingn’71]

B-body trans ? 833, you will end up cutting that hump..!! If there is ANY way you can trade the trans for an A body unit do it. Much easier for all things considered. Swingn’

 

[mygasser]

The trans I have is out of a B body, so I know I would need a different tail shaft housing. I am open to source something that fits better. The bell housing is aftermarket and I believe will accept a few different options, I guess I'll need to dig a little deeper.

or make an 'adapter' plate to move the shifter forward/up/down whatever you need. easier than changing/sourcing a different tail housing. the shifter rods can be shortened/bent to suit the new position easily too. if you can fit a big block in an 'a' body these jobs are simple, lol.
neil.

 

[oldkimmer]

I believe there is info on bigblockdart.com for most everything u want to do. Kim

 

[Daves69]

The trans I have is out of a B body

If it has the E-body shifter adapter bosses here's an option....

B/E body four-speed in an A-body

 

[AbodyBB]

So if you do have the B body four speed I would go to Brewers performance and buy a new output shaft and used tail housing. That avoids the excessive cutting of the floor pan. It also ensures you get the 68 and later 32 spline output.

 

[AbodyBB]

Also you have to use the 10.5 inch clutch bell housing unless you use the hydraulic clutch. The 11 inch doesn’t have the right bosses on it for the A body clutch linkage.

 

[outlet1265]

B-body trans ? 833, you will end up cutting that hump..!! If there is ANY way you can trade the trans for an A body unit do it. Much easier for all things considered. Swingn’

Yeah, I plan to mock it up and may have to find a different trans...

 

[outlet1265]

So if you do have the B body four speed I would go to Brewers performance and buy a new output shaft and used tail housing. That avoids the excessive cutting of the floor pan. It also ensures you get the 68 and later 32 spline output.

I'll look into that, Thanks