74 911, 4 speed box upgrading to a 5 speed

[matty74]

Howdy,

I have a 74 911 with 4 speed manual box, which I don't fancy much I want to go to 5 speed with closer ratio's.

Do I need a new box? There is a guy who's selling a 915 for 1K through the porsche club that is stripped down and cleaned, I just need to get it reassembled and put in my car.

Any suggestions for a course should I get my existing box rebuilt? Can I add a 5th gear to my existing box?

Should I get the 915 have it built with new seals all the syncro are OK just needs reassembly.

what do you guys reckon I should do?

[Shuie]

Are you sure you dont have a 915 already? A '74 should have a magnesium case 915 with the nice short ring & pinion.

[matty74]

Yeah I think so It is a magniesium case, but can I add the extra gear?

[Adam]

Not really - I just did this conversion. Click here for my thread with rudimentary pics.

The car is a lot more fun to drive now...

[Early_S_Man]

Matty,

Yes, you can convert the 4-speed to a 5-speed ... but it would probably be fairly costly, as you would probably need at least three new gearsets, and other parts associated with fifth gear that your 915 now has spacers residing there in place.

If the budget will allow ... do both -- rebuild yours, and get the other one, too, so you will have a spare transaxle for the future!

[rdane]

I'd be interested in buying your 4 speed...

[matty74]

Yeah I'm in sydney