5sp tranny swap for 1977 3.0 911

[sharky95127]

Guys/Gals,

I have a 4sp tranny that must have swap along with 3.0 motor into my 76 911 since they only with 2.7 motor. I love the 3.0 motor but do not like the 4sp since I'm running 4K RPM at 70-75mph.

Questions:
1. Is there a 5sp tranny for the 3.0 motor without breaking the bank. I will exchange it w/ the 4sp that I have now. What is the going price for a 5sp used?

2. On the 5th gear, what RPM should I expect at 70mph?

3. Will expect much less in acceleration time? I don't drive hard at all on my 911 baby? I drive it for the classic look mostly.

4. Any difficulty should I expect for a swap?

I appreciate anyone and everyone advice on this. Any links of the success swap or sale of a 5sp tranny would be appreciate.

Thanks!
Nathan
77 911sc 3.0

[Bill Verburg]

Originally Posted by sharky95127

Guys/Gals,

I have a 4sp tranny that must have swap along with 3.0 motor into my 76 911 since they only with 2.7 motor. I love the 3.0 motor but do not like the 4sp since I'm running 4K RPM at 70-75mph.

Questions:
1. Is there a 5sp tranny for the 3.0 motor without breaking the bank. I will exchange it w/ the 4sp that I have now. What is the going price for a 5sp used?

2. On the 5th gear, what RPM should I expect at 70mph?

3. Will expect much less in acceleration time? I don't drive hard at all on my 911 baby? I drive it for the classic look mostly.

4. Any difficulty should I expect for a swap?

I appreciate anyone and everyone advice on this. Any links of the success swap or sale of a 5sp tranny would be appreciate.

Thanks!
Nathan
77 911sc 3.0

Look for a '76 -86 915, these will all ave the electric speedometer that you have and will also have drive flanges compatible w/ what y0u have now

RPM @ 70 will vary w/ the transmission and tire diameter, a little lower for taller tires a little higher for shorter
the following are w/ 245/45 x16 tires
915/44 from a '76 S or Carrera 67mph 3000
915/61 or /63 from '78-79 SC 67@3000
915/62 from a '80-83 RoW SC 70@3000
915/67, 69, 71 from '84 -86 RoW Carrera 72@3000
915/68, 70, 73 from a '84 -86 US Carrera 70@3000

[sharky95127]

thanks Bill. Great information for me to start research.

Nathan

[Dodge Man]

Since you have a 3.0 you may want to go for the 78 up aluminum case 915. You may want to research how much a good rebuilt unit costs from a reputable house like California Motorsports or Patrick Motorsports to set your benchmark for cost & quality of a rebuild. 915 internal parts are expensive and you can easily spend $1000 to $2000 just in parts to rebuild a 915 properly. I would be very suspect of the $1200-$1500 rebuilt units out there (aka MM). I am finishing up my 915 quest and I found that you can get a used 78-79 915 trans from about $800 (condition unknown) as a starting point. Lots of good information here on Pelican. Good luck.

[Joe Bob]

A "Good" rebuild and CA motorsports or PMS are not words what I would use in the same sentence.

I would talk to your local PCA for recommended shops. John Walker has a good rep. It all depends on your budget and location.

[RWebb]

there is a best year for trans. thread that can help you narrow it down

a Mg case trans. with various mods can be made very strong - stronger than most Al cased units and a bit lighter also, if you race

besides gear ratios (for the 3L vs. 3.2L), you need to watch out for CV joint flange compatibility

you can mix & match gears for $$ based on the many helpful charts Bill has posted over the years