1984 915 in a 1975

[mreid]

Is this a bolt in or do I need to change some parts? Thanks!

[Peter Zimmermann]

Clutch linkage is completely different. Axles/CV joints will be a challenge. You will need an electronic speedometer and will need to wire it (and remove the old speedo, cable, etc.).

[Shaun @ Tru6]

75 was a transition year into the 100mm CVs so you may get lucky there. otherwise as Peter says, you have to wire up a later speedometer.

[Roger 911]

I just swapped a '84 engine and tranny into my '72. As Peter indicated, the axles and speedo need to be swapped as well. I kept the original '72 style clutch mechanism in mine. You need one of these Welcome to Windrush Evolutions - WEVO - Porsche Products I think you also need to retain the early shaft for the throw out fork as well. In the end, it really wasn't difficult, once you know what you have to replace.

Roger

[mreid]

Would it be better to keep the 1975 915?

[silver911rdb]

Doesn't the 75 still have the 7:31 r&p vs the 84 with a 8:31? The 7:31 will be snappier. Not sure which year they transitioned to the 8:31

[Roger 911]

Originally Posted by mreid

Would it be better to keep the 1975 915?

That really depends on a lot of things. You do need to verify what R&P you have. This may help; 915 TRANSAXLE SPECIFICATIONS-GBOX Transmission Look on the bottom rib of your diff housing to see if you can still see the tranny number, e.g., "915/43", etc.

What motor are you running? How do you use the car? What are you trying to achieve with the tranny swap? What is the mileage/condition of each tranny?

In my case, I was swapping in the 3.2 and had the option to acquire the matching 915, with LSD, in great shape. My '72 915 was open diff, and needed some work anyway. I am very happy with the combination of the 3.2 and the taller gearing. However, I probably would not be so pleased with this gearbox and a smaller displacement motor (2.0-2.4 with S cams, etc).

Roger

[Peter Zimmermann]

Originally Posted by silver911rdb

Doesn't the 75 still have the 7:31 r&p vs the 84 with a 8:31? The 7:31 will be snappier. Not sure which year they transitioned to the 8:31

1975 models are the first year for the 8:31 r&p.