the 3 spd gearbox on the back of my slant is the stock box & i'd like to keep it. although i have been told they are the weak link in the drive line . i know nothing about them but would really like to keep it. my question is what can i do to the 3 spd & clutch to make it more durable? it won't be a weekly strip car, but it will see some quick acceleration & swift 1 - 2nd gear changes. & the odd 1 wheeler .

Odd 1 wheeler?

R u taking it off road?

The clutch and 3 spd wont last long with any clutch dumps. The only thing you can you with the stock box is replace it with something better,,,,,thats what Chryco did (4 spd).

The rear diff will eat spider gears when you do peg leg peelouts.

Noone ever did a swift 1-2 with the stock column shift without hanging up the linkage.

If you want to keep that setup you will need to be satisfied with sedate performance .

_________________
Yeah....Im the one who destroyed this rare, vintage automobile.....

The late A-230 is a little better but it will complain while being under load in a 10:1 SCR motor until it's in 3rd (but you are on the last part of the 1/4 at that point)...Keeping clutches behind said motor also was problematic... Going to another transmission will help greatly.
Correct, the linkage binds up and is easier to just wind up hard in 1 and quick shift to 3rd...which then dumps the rpms and lugs the engine...sorta works if you get up to 35 in 1st....

-D.Idiot

ok thats what i have heard also. is there a 904 with a electric over drive ? i mean could i have a 3 spd coloum shift with a button to engauge the over drive ? i just want to keep the bench seat if i could. if i have to change the bench seat out i'd much rather 5 spd manual or a 4 speed auto.

i have spoken to a few people this week about the 3 speed manual box. all reckon that it's not that bad but the clutch is the weak link, heaps of cars were raced with the 3 spd & the aussie chargers used 3 spds at bathurst & other racing behind the mighty e49 265 hemi. one of the guy's races a slant six in hamster class with the 3 spd , & knows a place that makes custom clutches for them for around $300 . he has not had any problems since.

In the USA, the A-body with a floor shift 3 or 4 speed was standard with a benchseat...if it was a console car it'd have to be a bucket seat car...the curve of the stock shift handle goes right over the top of the bench (my dad's Duster was a bench seat OD 4 speed)... your cars being right hand drive, I'm not sure how the US floor shift would look/work in your car since the floor hump is offset to the left side of the tranny hump when sitting in the car.
Here it's called the A-500, but the tailshaft is larger and requires cutting of the floor pans and some alteration of the crossmember, it also only works with the 318 engine bolt pattern so here we have to use an adapter to fit it to the slant...(is time and some $$$)

Plan B there would be to use a gear vendors OD unit installed on the back of the 904 (but is $$$)

ok A-500 . can it take all the same good bits as a 904? but i imagine the OD will weaken the unit? & is it a electric over drive? so i can use a switch on the dash for the over drive? does it change the harmonic ballancer & balance of the engine ?