4+3 to ZF6 ????
Drifting
Joined: Aug 2002
Posts: 1,775
Likes: 125
From: Birmingham AL
From what I have read on here, it is definitely not a direct fit. The biggest problem that you will encounter will be the shape of the transmission tunnel. The 4+3 shifter actually mounts to the tunnel whereas the ZF6 shifter is on the back on the transmission. Two totally different holes. The 4+3 tunnel will have to be fiberglassed as the shifter hole is enormous and on the side. The ZF shifter will need a hole in the top. You can probably use your pedals and driveshaft but everything else is different. Then there is the unique '89 console plate to be found.
Advanced
Joined: Jan 2007
Posts: 63
Likes: 0
From: Hamilton ontario
I converted my 84,you will have to modify the tunnel for sure. but it wasnt that bad.i got the floor section from a salvage yard.,i bought a flywheel and clutch from carolina clutch for a zf conversion, i had to make a .040 shim to move the bell housing back so clutch would not bind up. I used a drive shaft from a 84 automatic car just changed trans yoke and the beam was from an 84 car. I used pedals from a 90
and i must say when complete it was one of the best things I have done on the car.
and i must say when complete it was one of the best things I have done on the car.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
http://members.cisdi.com/~anesthes/zf6/
Only need to change to a ZF6 yoke on your existing driveshaft
Only need to change to a ZF6 yoke on your existing driveshaft
Pro
Joined: Mar 1999
Posts: 678
Likes: 0
From: Oslo, Norway
Hi. I have an 85 with 4+3 and had a noise in the gearbox and thought of changing. After having investigated a lot I found that going to ZF was much changes.
My preferred change would be thr Tremec or Keisler kit which is nearly a bolt on and the gearbox manage more than enough torque. There was also a Richmond box but that was quite expensive.
For me I though I had to change the gearbox but it showed that it was the front bearing . So I had an overhaul of the gearbox as it was a late version and it cost 1/3 of a new totally.
Have driven a corvette with TKO (Tremec or keislerkit) and the very short shifting and preciseness was way better than the 4+3.
My preferred change would be thr Tremec or Keisler kit which is nearly a bolt on and the gearbox manage more than enough torque. There was also a Richmond box but that was quite expensive.
For me I though I had to change the gearbox but it showed that it was the front bearing . So I had an overhaul of the gearbox as it was a late version and it cost 1/3 of a new totally.
Have driven a corvette with TKO (Tremec or keislerkit) and the very short shifting and preciseness was way better than the 4+3.
Melting Slicks
Joined: Mar 2003
Posts: 2,512
Likes: 49
From: Franklin IN
T-56 for me
I'm going with a T-56 6 speed out of a mid 90's "F" body The ZF is a great trans but very expensive to repair. For the T-56 I had to be sure it was from a LT-1 car. I can use my orginal clutch set up. I did have to buy a bracket to go on the back of he trans to adapt the trans. I'm buying a special adjustible hydraulic throw out bearing. Yes I will have to do the trans tunnel mod but a little screen glass mat and resin I'll be all set. The trans cost me 1250.00 500.00 more for the bracket and throwout bearing.
A Richmond is a bolt in except for the tunnel which has to be modified in any case. However I have heard that they whine as they have straight cut gears. That is what the NASCAR guys use is straight cut gears. There are guys out there with Richmonds for sale they usuallly want about 2800 to start.
A Richmond is a bolt in except for the tunnel which has to be modified in any case. However I have heard that they whine as they have straight cut gears. That is what the NASCAR guys use is straight cut gears. There are guys out there with Richmonds for sale they usuallly want about 2800 to start.
Last edited by 87bob; Apr 7, 2011 at 01:42 PM.
