4-spd gurus out there I need to pick your brain!!!

[Matts68bird]

In the process of doing a conversion on my 68 roadrunner, At one time someone ran a 4-spd in it then went to a floor shift 727. Ive been talking with some of the members here in the forums. They helped me gain more knowlege on the pieces I need, but with that comes more questions...

I already have the correct steering column and well as the pedals, but I will need everything else. (the motor is a mild 383 and most likely will be getting a 23 spline trans)

Here are the questions:
1. Size of bellhousing, stocks for my year is a 10 1/2" right?
2. What would be the advantage/ price difference with an 11"?
3. Also late model use aluminum over cast? Is there a plus or a minus to one or the other?
4. Motorwork needed on crank to accept the 4-speed, what am I in for?
5. Crossmember mods, or should I buy a repo piece?


Thanks in advance,
Matt

 

[lewtot184]

'68 road runner would've had a 143 tooth flywheel with an 11" clutch/pressure plate and matching bell housing.

 

[Daves69]

1. Size of bellhousing, stocks for my year is a 10 1/2" right?

I think both were available but the 11" was considered the HP set back then as I understand.
I'd tell you to first decide what clutch setup you want to run, make sure it's available, then investigate the bell and flywheel that will be needed.
The 10-1/2" and 11" scalloped clutch setup is going to need a 130 tooth flywheel and corresponding bell housing.
The aluminum bells were '70 and up and fit the 130 tooth flywheel.
The true 11" will need the 143 tooth flywheel and it's bell housing. I believe steel scatter shields have accommodations for either size. I know my Lakewood 3 piece does.

2. What would be the advantage/ price difference with an 11"?

Smaller 10-1/2" is lighter weight. More clearance. Probably more options available.

3. Also late model use aluminum over cast? Is there a plus or a minus to one or the other?

Aluminum lighter. Either is fine for street stuff. Neither is recommended for racing.

4. Motorwork needed on crank to accept the 4-speed, what am I in for?

Maybe little or none if the crank is drilled for the input shaft bushing already. My '68 383 RR was drilled. I just had to fit the bushing. Then too a lot of folks are chopping off a section of the input and using the bearing setup in the rear of the crank instead of bushing it. Use extreme caution if you do this. The shaft is a lot harder to make longer if you cut it too short. Another caution, you don't want the input shaft bottoming out if the crank bore isn't deep enough.

5. Crossmember mods, or should I buy a repo piece?

I don't recall if I had to swap or used the same. My complete setup came out of a '69 RR. I converted my '68 RR way back in '75.

Some info here that may help you ...........
http://www.bigblockdart.com/techpages/4sptech.shtml

Some depths I measured on a 440 crank (diameter is incorrect)......

 

[moparwacko]

Should have an 11in clutch, 143 tooth flywheel I believe as stock.
Use a stock pilot bushing to see if it was reamed from factory, and is deep enough. Measure it, somebody on here will chime in those dimensions I'm sure. If deep enough, but not reamed to final size, there used to be a undersized bushing. They are very hard to come by, but somebody up in the Midwest was making them. I may know someone.....ahem that has a stash if you can't locate one.
Trans mount, just modify yours. I've done lots of them, welder up. Cut the auto setup off, fabricate the top bracket - Voila, 4 spd mount.

 

[R/T]

Depends on what crank you have, if its reemed for a bushing then maybe a bushing is there, if not then go with the needle bearing, its cheaper at the local auto parts, just wont last as long as the bronze oiled bushing. If its a diaphragm clutch then you wont need the big overcenter spring on the pedal. Buy a real clutch bearing , the one that comes with the clutch kit is garbage, torque down the clutch with the transmission shaft if you can, the plastic one supplied wont line it up, Rick Ehrenberg sells NOS bolt kits for the flywheel .68 was 11". Ground the trans neutral post on the stater relay. Reverse light hook 2 wires to bulkhead D and C.

 

[NJRR]

Brewer's Performance website is a good reference for 4 speed parts. They have a lot of part numbers and specs listed with pricing as a guide.

 

[rumblefish360]

I do believe the cross member and trans mount should be used he same for the 727 & 833.

 

[NJRR]

I do believe the cross member and trans mount should be used he same for the 727 & 833.

They use the same in the 70. When I did my 727 to 833 conversion in my 70 RR used the same one. Not sure about 68 or 69.

 

[Matts68bird]

Wow you guys killed it. Thanks so much!! This helps me along my journey. Some of your guys I will be contacting once i get time. I am suppose to be cooking dinner right now! whoops, this is more important. The old lady can wait.

Matt

 

[Matts68bird]

Thank you all, especially Daves69. You were able to answer everything. All you guys rock, really helps a younger dude like me with all this stuff. If you guys are even in town drinks on me!

 

[Matts68bird]

Motorwacko. So from what your saying, as well as a couple others here, and what I'm researching for my 383 4 barrel car, the 11'' is the correct size with 143 tooth flywheel. As well as the mod for the mount I should be able to do that no problem.

Other question is bearing retainer size. it seems that there are a couple diff sizes but the ones that I need to look at is a 4.80" or 4.35"? I'm not sure...

(I need 4.80" right for my year?) are they universal w/ diff bearings that I can swap, or I need to make sure it matches up to the trans? Just want to feel like I'm understanding this and make sure I get all the right parts.
Please chim in if anyone can help or correct me.
Thanks,
Matt

 

[Matts68bird]

Also for 11" flywheels, do I need to run one or the other, seems ppl have ran 130 and 143 tooth..

 

[moparwacko]

Correct, 383 4bbl is a 143 tooth flywheel.
11" clutch is correct.
4.80 brg retainer is correct for 23 spline.
Bell housing must match (4.80), mine is cast# 2892626.
I would strongly suggest buying as complete a setup as possible.

 

[lewtot184]

bellhousings are different between 130 tooth and 143 tooth flywheels.

 

[Matts68bird]

Lewton184 I take it then that the 130 tooth is for a 10.5", and the 143 tooth is for the 11"? Is this correct?

If so, that would make much more sense due to the different number of teeth. If they are the same pitch it would result in a different sized flywheel. All the teeth are use for the starter anyhow.

thanks,
matt

 

[Matts68bird]

the flywheels are the diff sizes so that is answered.

As for clutch forks for "1966-up b body's" between the 10.5" bell housing and the 11" are they the same..?

Looks to only be one size on Brewers site . Measures 10 7/8"

 

[Matts68bird]

Also if I were to get a 11" bell housing with a 4.80" hole, and mate it with a 23 spline trans with a bearing retainer of 4.38" and shaft length of 1.248"
Brewers makes a spacer if I can't turn one down on the lathe at work that adapts the two.

Question is...???
Does the bolt holes line up the same? And does the Bearing retainer shaft length play a role at all?

(Seems the only variance is the overdrive trans and the 18 spline hemis) so I'm my case I shouldn't have an issue

 

[lewtot184]

Lewton184 I take it then that the 130 tooth is for a 10.5", and the 143 tooth is for the 11"? Is this correct?

If so, that would make much more sense due to the different number of teeth. If they are the same pitch it would result in a different sized flywheel. All the teeth are use for the starter anyhow.

thanks,
matt

1970 used a 130 tooth flywheel with an "11" scalloped" pressure plate. stick with 143 tooth/11" clutch 1968 stuff and you'd be assured of everything bolting up.