1985 700r4 in a 75 Vette.......
Thread Starter
Burning Brakes
Joined: Feb 2011
Posts: 849
Likes: 0
From: Woodland California
1985 700r4 in a 75 Vette.......
Found a reasonably priced 700r4 Transmission in a 1985 corvette to replace my Th350 in my 75 Sting Ray.
Is this a straight swap?
Anything special to consider?
Ralph
Is this a straight swap?
Anything special to consider?
Ralph
Thread Starter
Burning Brakes
Joined: Feb 2011
Posts: 849
Likes: 0
From: Woodland California
I'm putting out less than 350 hp and the car is just a cruiser.
What was the weak spot in the Tranny?
Ralph
Drifting
Joined: Jul 2009
Posts: 1,534
Likes: 14
From: Dallas-Fort Worth TX
I swapped mine for a later better core. I think I have a 89 or 90 core. I think the 87-92 were the stronger ones. I may be wrong. The one in my 82 had originally been replaced. It was stamped remanufactured for GM on the side. But I opted for a beefed up 700 in a later core due to my engine upgrade. I still have the old 700r, it worked fine, and its for sale.
Melting Slicks
Joined: Dec 2009
Posts: 3,235
Likes: 658
From: Thunder Bay
I have a 700R4 in my '79. I understand the 200-4R is an easier swap but the 700R4 is no big deal if you have any mechanical ability at all. You don't need to change the crossmember, and you can buy the parts to bolt it up as GM used the 700R4 in the Corvette in '82. You just have to make sure you get the right tailshaft housing.
You will have to shorten the driveshaft but that's no big deal. Measure what you need and take it to a machine shop with driveshaft experience. The biggest problem is routing the exhaust. The 700 is wider than the TH350 just in front of the crossmember and its a challenge to get the pipe past the trans and through the crossmember. I modified my crossmember to move the exhaust hole outboard about 2". You also have to move the park brake cable pulley. Just cut it off, move it to where it works and weld it back on.
You'll love the swap. I went from 16 mpg to 25 (imperial gallons). Much more driveable on the highway.
You will have to shorten the driveshaft but that's no big deal. Measure what you need and take it to a machine shop with driveshaft experience. The biggest problem is routing the exhaust. The 700 is wider than the TH350 just in front of the crossmember and its a challenge to get the pipe past the trans and through the crossmember. I modified my crossmember to move the exhaust hole outboard about 2". You also have to move the park brake cable pulley. Just cut it off, move it to where it works and weld it back on.
You'll love the swap. I went from 16 mpg to 25 (imperial gallons). Much more driveable on the highway.
