Thoughts on a TKO in a 70 RS 396

C4Racer

Veteran Member
Oct 26, 2018
816
$1500 I would consider.

But the price on bowlers web site is $5995 for that trans and the magnum is $3K. So it’s $3K more. Unless I am missing something.

Ratio wise that trans with a 3.89 gear is pretty similar to a magnum close ratio with a 3.50 or 3.70 gear. Main difference is 4th isn’t as tall which is a pretty nice gear. For my engine and tire size that Brings top speed in 4th to 130 with your setup and 140 for the 3.5 gear and 3.7 is 135.
 

71RS/SS396

Veteran Member
Aug 26, 2008
2,640
Wake Forest NC
$1500 I would consider.

But the price on bowlers web site is $5995 for that trans and the magnum is $3K. So it’s $3K more. Unless I am missing something.

Ratio wise that trans with a 3.89 gear is pretty similar to a magnum close ratio with a 3.50 or 3.70 gear. Main difference is 4th isn’t as tall which is a pretty nice gear. For my engine and tire size that Brings top speed in 4th to 130 with your setup and 140 for the 3.5 gear and 3.7 is 135.
The price has gone since I purchased my last one then, I paid $4500 for the last one.
 

OldDog

New Member
Jun 13, 2000
15
Churchville, MD, USA
... I have a 1970 Z/28 RS 396 mild cam 3.73 12 bolt pos rear end with M22 4 speed ...I’m taching 3 grand or more at 70mph ... needs a new clutch so thinking the TKO 600 is my best option for a drop in , opinions, options , what can I expect rpm wise at 70-75 mph and current prices ?
IMO I would look into "Gear Vendors" who makes an overdrive that attaches to your current transmission...you basically replace tail section, handles lots of horsepower and cost is a little less (i.e., and in the amount of work) than changing out your trans.
 

Plant Engineer

Veteran Member
May 17, 2017
413
Fort Mill SC
I dont get the need for overdrive. It really limits your cam selection and the ROI is absurdly long. These engines were made to run at 3000 RPM all day long. It doesnt hurt anything.
 

NeoNeuro

Veteran Member
Aug 4, 2014
208
Panama City, FL
IMO I would look into "Gear Vendors" who makes an overdrive that attaches to your current transmission...you basically replace tail section, handles lots of horsepower and cost is a little less (i.e., and in the amount of work) than changing out your trans.
My understanding is that these require some fairly significant modifications to the floor pan to fit in 2nd gens. That's why you don't see more of them.
 

G72Zed

Veteran Member
Sep 8, 2015
4,418
Canada
I dont get the need for overdrive. It really limits your cam selection and the ROI is absurdly long. These engines were made to run at 3000 RPM all day long. It doesnt hurt anything.

x2 ^^ You are right on with that quote.

But, back in the day, with the original bias ply tires and suspension, perhaps 62 mph hwy cruise speed was OK and the norm back then?

Today on the highway, (at least where I live), 62 mph (100 KPH), your a pylon and/or obstacle at that speed and risk causing and accident, or being part of one. not to mention taking forever to get somewhere.
 

Peter Wollman

Member
Mar 4, 2012
46
Alamo, CA
The one transmission that I left out of the discussion is the Mcleod 5 speed, but I have no idea about its high rpm shifting ability. Also, the torque rating spec was dropped to 500FT/LBS by Mcleod so I am not sure about its overall strength. However, it is stronger than the Muncie and I have never broken a Muncie over the years. I don’t do any clutch dumping, so 500FT/LBS should be strong enough. The Mcleod 5 speed gear ratio is not as perfect as the TKO 600 RR or Richmond varieties, but it's a fairly good match with my 3.55 rear end. Does anyone have real world experience with the newer Mcleod 5 speeds, it seems that the first release of them didn’t have great reviews?
 

flht99b

Veteran Member
Nov 28, 2014
842
Knoxville, TN
The TKO 600 with the .64 5th gear, 4.10 rear gear and 28" tire works BUT to me the drop from 4th 1 to1 ratio to 5th .64 ratio is a lot, like nearly 900 rpm. Depending on the cam and engine torque it is easy to drag an engine down. I find I have to be at least 3200 rpm in 4th before shifting into 5th. If I were to do it over I would look at between a 3.55 to 3.73 gear with a 26 to 27" tire with the TKO 600. It seems a lot of off highway driving I do is in the 50 to 60mph range which means my car is in 4th gear turning over 3,000rpm. The 6 speed trans is the way to go but fitment and cost are issues.
 




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