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Tranny Swap
HI BOB,
THE FOUR SPEED TOP LOADER ON ERA-273 BECAME VERY UNFRIENDLY. WHEN I DRAINED IT I FOUND MORE MISSING TEETH THAN IN SEVERAL WEST VIRGINIA COUNTIES. I'M VERY INTERESTED IN REPLACING IT WITH A TREMEC 600, FIVE SPEED. THE .64 OVERDRIVE RATIO WILL GIVE ME A MUCH NICER CRUISE CONFIGURATION. IS THIS SWAP DO-ABLE?? KEISLER ENGINEERING ALLEGEDLY HAS A REPLACEMENT "KIT" WITH THE NECESSARY ADAPTERS. I'VE NEVER HEARD OF THEM BEFORE BUT ONE OF THE CACC CLUB MEMBERS HAS RECOMMENDED THEM. I GUESS MY MAIN CONCERN IS ADAPTING THE REAR TRANNY MOUNT TO THE ERA 427 CHASSIS. ANY THOUGHTS/SUGGESTIONS YOU MIGHT HAVE ON THIS WILL BE GREATLY APPRECIATED. THANKS - AND - Y'ALL HAVE AREALLY GREAT DAY. BLACKJACK |
Just remember who lost the war!
Chet - on the winning side in WV |
The Tremec mounts about 1.25" further back than the Top-loader. We never attempted to put the Tremec into an early car like yours, so I can't say definitely whether it would fit by moving the support back. You will probably have to notch the X member for clearance.
On the newer cars with the X member moved back about 2" from where yours is located, we still have to trim a bit off the Tremec casting to clear the passenger's side of the tunnel. The hole for the shift lever is different too, so you'll have to re-rug the tunnel. The Bottom Line: It can be done but some cutting and welding will be required. |
Bear in mind that OD final drive ratio will really drop the cruise rpm. I hope your motor can handle in the low 2000 rpm range without complaining.
On the other hand, that first gear ratio will be a real "tire smoker"! My new Comp Cam profile pulls nicely from about 1800, so that trans would work fine for my setup. 3:31 rear gear, all though I love my top loader. :D |
THANKS VERY MUCH, BOB. I'LL HAVE TO DO SOME CLOSE MEASURING. IT MIGHT BE EASIER TO REINSTALL THE TOP LOADER AND CHANGE THE REAR END GEARS.
SLICK: YEAH, IT SHOULD HANDLE LOW 2'S AT CRUISE - - A LOT BETTER THAN IT HANDLES LOW 4'S. Y'ALL HAVE A REALLY GREAT DAY. BLACKJACK |
BJ:
What about a Richmond 4+1. Top is 1:1, but with a rear gear of 3.08 makes a nice cruiser. What rear gear do you hae? Jim |
HI JIM,
IT'S A 3.50 OR 3.55. I'M NOT FAMILIAR WITH THE RICHMOND 4+1. THANKS, JACK |
3:50 DAM! Eh eh, that thing is all ready a "tire smoker". You must use 2nd to take off. :D
Richmond would have an ultra low 1st gear ratio, useless with a 3:50 rear (unless your pulling stumps or wheelies). And since high gear is 1 to 1, no difference in crusie rpm. Nice with a 3:08. You know, that Tremec would work out OK with that rear gear. Just bear in mind you will still have an ultra low 1st gear (lower than you have now). Hmmmm,,,, an OD style trans, close ratio with a 2.2-2.5 1st ratio would be just the ticket. I don't think they make one! :D |
Top Loader gearing
Close Ratio: 2.32,1.69.1.29.1.0
Wide Ratio: 2.78,1.93,1.36,1.0 With a 3:31 gear 3000 rpm at 71 mph for either trans. With a 3:55 gear 3000 rpm at 67 mph for either trans. 26.5" tire. In the low fours, your hauling a$$, or have small tires. :D |
BJ:
I have a Tremec TKO in my FIA with a 3:31 rear. If I were to do it again with this trans, I would use a 3:54 rear. It's a bit too long with my small block Gurney motor. In my first two big block cars I used the Richmond 5 speed with a 2:88 rear in the first car and 3:08 in the second. They were great; fourth gear was like a top loader with a 3:54 and then you shifted over into fifth and just cruised. Jim |
The first four gears in the Tremec 600 are almost identical to the wide-ratio Toploader. First gear is a little short with the 3.54 but still well out of the stump-puller category. I think using either a 3.31 or 3.54 differential would be acceptable.
Just remember that the .68 fifth gear is strictly a cruising gear - accelleration is only going to be noticed by a current Hyundai owner. :rolleyes: Unless your car is supercharged... :MECOOL: |
Black J,
I have a Richmond with 3.07. Pulls in all 5 gears. Car did complain a little bit when I mistakenly tried to start it in 4th gear going up a hill. At the time I could not figure out what the heck was happening. Gave a bit more gas and chirped the tires and thought - good - problem solved. SHifted into what I thought was 3rd and it pulled like a champ even though it was in 5th. I caught on when I tried to put it into 6th :eek: :p 5th gear provides a nice cruising gear. To the point where you can have a very good conversation with the passenger without raising the decibel level in your voice. Dropping back into 4th provides you all the fun stuff straightaway again. I claim no technical capabilities, but it is my understanding that the Richmond can handle the higher horsepower more effectively than the Tremac. (please don't shoot me Tremac fans :) ) |
THANKS GUYS,
HOW READILY WILL A RICHMOND 5 SPEED FIT INTO AN EARLY ERA 427??? BJ |
You might want to check out this comparison between a TKO and a Richmond 5 speed. The Richmond is a 1 to 1 ratio in 5th gear, same as a top loader. No difference in cruise rpm!!!
http://www.5speedtransmissions.com/5sp_comparison.html 6 speed is the way to go. It appears there are quite a bit of 6th ratios available, (5th is still 1 to 1) which is really nice! You could dial in your best cruise rpm\mph combo. 1st gear would still be to low, in my opinion. Perhaps you can spec a higher 1st gear ratio as well? Cake AND eat it to! :D |
Black -- for what it is worth my ERA is #389 which isn't far off your car number.
Mr. Putnam would be the one with the real answer though |
The Richmond 5-speed definitely requires that the X member be moved back. It's physically longer and the mounting holes are 2" further back than the Tremec. (Don't even think about the RG 6 speed...) Except for the slightly-off shifter location, there is little disadvantage to using the Tremec rather than the Richmond.
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I'm running the Richmond 5 speed with 2.88 gears. I love the gearing. All 5 gears are readily "useable" and at 75 mph I'm running about 2600 rpms. My only complaint is that it's not a real smooth shifting transmission. If I'm really on the gas and trying to speed shift, I often miss. Very frustrating when it happens. I'm not familiar with how well a Tremec or a toploader shifts but I use to have a Chevelle with a Muncie 4 speed and shifting that was like slicing butter. By comparison, my Richmond is more like trying to slice the bread.
Chris |
Pretty Boy,
As we talked about at the Herndon Drink-Ripper's-Beer gathering, I think the 600 offers some advantages. Although the Richmond may have held up better than the old TKO, neither it or the old TKO are rated for 600 ft-lbs like the TKO600. I have a 3.23 rear with the .82 5th and I think that is about ideal. A 3.31 would be about the same. Cruising at 70 is about 2300 rpm. My engine doesn't like below 2000 cruising and I think you will be close with a .68 5th. I haven't run the numbers, so I don't know for sure. |
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