71 Transmission Change
Thread Starter
Heel & Toe
Joined: Jun 2009
Posts: 22
Likes: 0
From: Austin Texas
71 Transmission Change
I have a 71 3-speed automatic 350/270; not a dragster obviously, but still a lot of fun to drive. Top speed I can get her to is just shy of 100 though; just not enough in that 3rd gear to keep those RPMs climbing.
It's been recommended to me to put in a 4-speed auto tranny (or 3-speed with overdrive) to improve the top-end speed.
And before anyone suggests it, I'm NOT interested in putting in a manual tranny; just want to get those RPMs down at higher speeds.
Has anyone done this? It's been recommended to me to put in a 700r4.
Any feedback/advice, good or bad, is appreciated.
m
It's been recommended to me to put in a 4-speed auto tranny (or 3-speed with overdrive) to improve the top-end speed.
And before anyone suggests it, I'm NOT interested in putting in a manual tranny; just want to get those RPMs down at higher speeds.
Has anyone done this? It's been recommended to me to put in a 700r4.
Any feedback/advice, good or bad, is appreciated.
m
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
i put in a 700r4 and i like it.....got to www700r4com....they are BTO and they have all the info and kits you need. the task of swapping it on a scale of 1-10 for difficulty with 10 being the hardest is about a 5......the amount of effort involved is more like an 8 or 9.....not hard just a lot of different things that have to be done.....its a fun project with a big return
if you have a BG speed demon i have the brackerty from BTO that you need for this.
some guys like the 2004r as opposed to the 700r4.....just take a look at the trans gear spaceing and then compare it to your rear end ratio....the 2004r works better with lower gear ratios like 4.11 and the 700r4 works better with 3.08.....its all a matter of preference and their are strong opinions on both sides...
if you have a BG speed demon i have the brackerty from BTO that you need for this.
some guys like the 2004r as opposed to the 700r4.....just take a look at the trans gear spaceing and then compare it to your rear end ratio....the 2004r works better with lower gear ratios like 4.11 and the 700r4 works better with 3.08.....its all a matter of preference and their are strong opinions on both sides...
Last edited by bobs77vet; Nov 18, 2009 at 08:34 PM.
Thread Starter
Heel & Toe
Joined: Jun 2009
Posts: 22
Likes: 0
From: Austin Texas
Thanks Bobs77vet. That's what I'm hearing/reading as well; that although a little more difficult because of size/length, the 700r4 is the preferred choice for durability. My rear end does have a lower gear ratio (although I may change that to a 3.08 in this process as well).
I've been told too that I'll have to dump my Roch Quadrajet carb in favor of a Carter/Edelbrock because the 700r4 TV cable geometry won't work with the Quadrajet. Was that your experience as well?
I've been told too that I'll have to dump my Roch Quadrajet carb in favor of a Carter/Edelbrock because the 700r4 TV cable geometry won't work with the Quadrajet. Was that your experience as well?
Melting Slicks
Joined: Feb 2007
Posts: 2,136
Likes: 62
From: West Kingston RI
I could be wrong but I thought BTO had an adapter for your carb. I can't get on their site right now but check them out. I know they carry the wires you need for the lockup converter.
http://www.bowtieoverdrives.com/index.shtml
http://www.bowtieoverdrives.com/index.shtml
