Transmission question

[911Etarga]

I am in the market for a new (used) 915 for my '71E. I was wondering what years of 915 would best suit my car? I got an electronic speedo rebuilt to look like a '71, so I am set up for that, but my biggest concern is the gear ratios. The car currently has the 2.2E engine in it and a dead mag 915 (numbers are to scratched to see what they are). I found a '77sc 915, would this work well?

Thanks!
Brent

[Jim Sims]

Check for a plugged vent on top of transmission.

[RWebb]

the '77 escapes the bad designs of the earliest 915s.

it is actually stronger in some ways than the later Al transmissions & is lighter too

all Mg cased items need serious protection from corrosion

There is a thread with some tables in it on the "best transmission"

BUT the '75 & on tranny's have a 7:31 R&P (aka CWP), and
"the 7:31 R&P will lower ALL the gears."

see: http://forums.pelicanparts.com/porsche-911-technical-forum/400449-915-trans-gearsets-ring-pinion-change-post3852593.html#post3852593

[911Etarga]

Thanks for the feed back!!
I think I want the 7:31 for my 2.2. A little more power of the line would help.
Just for reference, should a 2.2E with carbs be able to out run a Civic? Mine wouldn't right now......
And in 5th there is nothing, I can't even get up a small hill without shifting into 4th (the only gear that seems to have power)
The engine was just rebuilt, so I am trying new jets (55) to see if that does anything.