switching from a 383 4 speed to a hemi 4 speed

[ckessel]

Check the diameter of the bearing retainer on the front of the trans. Hemi, which uses a 308 bearing, was one size. 23 spline uses a 307 bearing but there were two different od's of the retainers. One was same size as Hemi, the other smaller. Therefore if its too big, won't fit the bell and you'll need to find another proper size bell.

 

[Kilrbee]

To change from a 23 spline to 18 spline you will need to change..
The bellhousing & inspection cover .. larger bearing retainer OD
the flywheel.. 23 spline uses 10 1/2" clutch and 18 spline uses 11" clutch..
The throwout bearing is larger for the 18 spline
The clutch disk and pressure plate, obviously also..
You may also have to change the clutch fork, but I'm not sure on that..

as long as the mount location is the same NP, and you driveshaft will work also

 

[Fran Blacker]

70/71 Hemj's had 10.5 clutches. Yes the hole for bearing retainer is probably larger, that I can't answer. If you can't use original bellhousing you will need to index the bearing retainer hole. See kern dog thread on converting to a 5 speed. Not be negative but as mention earlier why switch to a Hemi 4 speed. If you have plans to stroke your 383 do it then.MO
The worms are coming out of the can.

 

[MCODECUDA]

To change from a 23 spline to 18 spline you will need to change..
The bellhousing & inspection cover .. larger bearing retainer OD
the flywheel.. 23 spline uses 10 1/2" clutch and 18 spline uses 11" clutch..
The throwout bearing is larger for the 18 spline
The clutch disk and pressure plate, obviously also..
You may also have to change the clutch fork, but I'm not sure on that..

as long as the mount location is the same NP, and you driveshaft will work also

If his 69 Roadrunner has the original bellhousing it has the 11” clutch and the larger 308 bearing and as long as his 18 spline transmission is not a 66 or 67 model it will bolt together. FYI, 66 and 67 18 spline transmissions used the 307 bearing retainer. The clutch forks are the same but like you stated the throw out bearing and clutch disk is different.

 

[sam dupont]

Mine bolted together, but the starter did not reach the ring gear. The guy I bought the trans from was NOT happy, but gave me the aluminum bellhousing from the 6 pack car and insisted on getting my original iron unit in trade.

 

[POMONAMISSEL]

in 70 the trans mount changed locations . the tail stock should interchange between the two .