Transmission replacement ??
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
Transmission replacement ??
Is there a particular year or model auto overdrive transmission that would "bolt" in without severe modification in my 74 LS4 Roadster? The original T400 is getting old and it really needs an overdrive gear. Runs 3000 rpm at 60 MPH. It's a shame to waste all that low end torque! Thanks y'all.
Melting Slicks
Joined: Aug 2012
Posts: 2,548
Likes: 379
From: Woodinville WA
the 700 case isn't really any larger than your 400 or wider for that matter - so it should fit within the space quite well...
now, 700R4 come in a number of flavors. You want one with all the updates and Corvette servos. I'd personally avoid the electronic controlled 4L60E (electronic 700R4). That said, if you have the bucks, it is nice to be able to exert such control over the transmission at just the touch of a button.
That said, 4L80E is quite a bit bigger (and unnecessary, IMO).
now, 700R4 come in a number of flavors. You want one with all the updates and Corvette servos. I'd personally avoid the electronic controlled 4L60E (electronic 700R4). That said, if you have the bucks, it is nice to be able to exert such control over the transmission at just the touch of a button.
That said, 4L80E is quite a bit bigger (and unnecessary, IMO).
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
Well, you can get a 700R4 from a C4 and install a torque converter that will match with your engine's performance. It shouldn't be a problem to handle that level of HP/torque. An O/D auto matches up better with a 3.36 or higher gear ratio; but with the torque of a BB, it would probably work OK down to a 3.08. What rear gear do you have in the car?
