For what it's worth, for decades I drove a 2.56 behind my 455. And honestly the engine could have worked great with much taller gears and a lockup convertor. Granted I've had EFI forever so I've had good engine control. But remember that the modern 3800 engines, which are half the size, do great at 70MPH and 2000RPM going up fairly steep portions of highway. So a 455 pushing an A-body down the highway takes SO little effort for our huge torque-monsters. After enough time with the 2.56 gears I wished I could have gotten some 2.29 gears or even put a GearVendors before my 2.56. If I hadn't been pushing so much nitrous, I would have gone for a 200-4R with lockup in front of my 2.56's. The engine now sits in our '73 LeSabre with 2.73 rearend & 28.5" tires- and even with the 5000# car (which often tows a car trailer so total load is around 9,000#-10,000#) the tall 2.73 gears are no problem at all for long highway cruises. In other words don't worry about a 0.64 top gear with 3.42's (=2.19), our big V8's are barely working on the highway and detonation shouldn't be an issue. Especially with a manual transmission where your converter isn't slipping at low RPM's. And if you are climbing the Rocky Mountains and worried about detonation, you can always drop to 4th gear. Just one guy's (unpopular) perspective... -Bob C.
You may be correct but I think with an automatic (non lock-up) it's a different story than with a manual (hence why the factory geared the manual cars higher). My only experience in this regard is blowing up the factory 3.23 in my '70 350 4-sp @ the '86 Nationals and finding a Chevelle rear on a Sunday (even got it delivered to the Ramada & a ride into town for some parts w/the guy) that was either 2.56 or 2.73. We made it home (across the Appalachians) but that car/engine did not like those gears at all. On the other hand, I went across the same mountains in my '70 Skylark w/factory 2.56 or 2.73's w/no issues whatsoever. Similar I guess w/my truck (7.3 IDI/manual/4.10). It does not like hills when loaded - I think an automatic w/3.73 would be handle it just as well (until the trans burned up of course).
Take all you can up top. The car won't care and you will not be full throttle screaming at +100 miles an hour for it to matter. Get the first gearing right for your combination, and never look back. (cuz you know their behind you...) My '64 Lark has 3.54 rear. 26.5 tires and the T-10 had 1.51 first. I was either breaking them loose when starting off, especially on any inclines, or having to slip the clutch way to much in stop and go driving. The 3.27 is perfect. (wide ratio) I can almost let the clutch out in first without any accelerator pedal, So, longer clutch life. I just can't offhand recommend that to you with 3.42 gears and a BBB, since my '64 has a nailhead. The curves on the two engines could be different enough. My '68 Lark has a BBB and auto with 3.42, and it is very different "feel". (It gets sideways real easy) Hope someone with a comparable manual, 3.42 BBB in an A-body can chime in and help narrow your focus.
What's it going in? That one looks like it is a hydraulic throwout bearing and center-mounted shifter.
From researching a couple installs of the TKX on some chevelles, it looks like the proprietary STX offset shifter from SST is about the only way to keep from having to cut the tunnel to prevent the shifter turret from hitting on cars with offset shifters. It looks like the stock tremec center mounted shift turret will hit the tunnel instead of coming up thru the factory offset opening. And it looks like we need the center of the shifter where it mounts to the shift handle to be 17-5/8" back from the trans mounting face and 2-1/2" to the left of trans centerline.
Do the tko shifters fit on the tkx? I can’t find info if they do or not but the plates look similar. If so there are offset hurst shifters.
From Modern Driveline? What did you have to do to get that? Here is my checkout page from my cart: Ground (UPS): $135.38
That was how it totaled on the invoice, and it shipped UPS ground. The purchase was May 2019, and I suspect due to all the mess for the last year has impacted that. I also called and spoke with James prior to placing the order, so that might have had affected the total. Call and talk to someone and see if they will give you a break. Cuz, that's like 948 dollars in dog money!
Here is my update, sorry it's long but there is a lot of good info: I checked about 5 of the Tremec distributors (Summit, Jegs, Pace Performance, MDL and of course American PowerTrain) and most or all of them say they are out of stock for weeks to months--Summit says they can ship in May. Also, all of them say there is a shipping charge, and some of them also charge state sales tax, which by itself could be over $100. Oh, and despite some of them claiming to have the .72 version in stock and--even let me put it in my shopping cart--the truth is that Tremec hasn't even MADE any of that version yet. I called Bowler Transmissions and immediately got a real live friendly human named Jeff on the line, who also was knowledgeable about Tremecs and specifically Tremecs for A-bodies, AND who gave me the scoop on why some vendors have some in stock while others won't have any in stock for months. Each distributor periodically gets an allotment of Tremecs, probably depending on their sales history. If a seller sells their allotment, they are "out of stock" until the next shipment comes. Bowler currently has about 15 TKXs of their most recent allotment in stock. BUT they are all the .68 units. I said "heck with it" and told him "Let's do it, I ain't waiting any longer." So I ordered one. Bowler charges $99 for shipping, but they don't charge any sales tax for my state. Oh, also, you get one of their shifter handles and a knob for free, so that eliminates the need to buy those. Probably at least a $100 value. He also told me that Bowler makes (or resells) an offset shifter stub for our tunnel-humps. It is $275, and if you order it at the time you order the TKX they will install it for free so it will arrive ready to go. I chose to wait on that, and if I need it, I will order it later and install it myself. He said I can expect delivery within a week or so. So, if you guys need a TKX and are okay with this version, Bowler seems to be a pretty good choice. Their number is 618-943-4856. Tell them Jeff with the '69 Buick told you they are a good outfit, and maybe they will send me a keychain or something. J/K That's it for now, but I do have a clutch question I will ask soon.
I paid $85 for the offset for my TKO 500. (From Modern Driveline). The stubs look like they are the same both (if it is only the stub and not any portion of the shifter), so before you spend $275, check around.
Wow, that is great to know. You may have just saved me about $200, in which case I owe you a (root) beer or two....hundred. P.S. I just got an email from UPS saying the TKX is scheduled to arrive in TWO days. I just placed the order this afternoon. That is fast shipping. I don't even know if my credit card has been charged yet, since it wasn't showing any recent charges an hour ago. I just re-ruptured a disc in my lower back today. I was thinking I would have time to heal before needing to carry 125 lbs. of tranny from my doorstep to my garage. I guessed wrong.
Here is my clutch question: I am thinking of getting either the Hays Street 650 Clutch, or the McLeod Street Extreme Clutch. They seem similar as far as how much torque they can handle, and they cost about the same ($350 for the kit which includes pressure plate). 1. Which is better for normal and occasional "spirited" driving? 2. Is one easier/lighter to depress than the other? (My knees are getting bad) 3. Should I choose neither one and go with a different setup? If so, what? 4. And will my stock 430 flywheel accept both a 10.5 and an 11-inch pressure plate? If so, which size is better? Thanks for any advice you have.
I am confused, Michael. I looked it up. Is this what you were referring to? https://www.moderndriveline.com/sho.../68-72-gto-lemans-tempest-shifter-tko500-600/
No. That is the shifter assembly. All I needed to get mine to line up was the offset lever to extend my offset to the left more than the offset lever the transmission came with. You might be fine going with only the lever, or you may need to purchase the shifter you listed. I would wait until you can get the transmission placed and see what you need. The shifter assembly is typically taken off when you install or pull the Tremec, so you can drop it in place after the tranny is installed. As far as the clutch. I had a pretty extreme McCleod back in the 70s on my '64 Special. (being more than 40 years ago, I cannot really speak about the products today) It had a pretty short throw and I almost had to "straight leg" at stoplights, and keep the seat belt tight. "Armor All" had just come out and I used it, and the clutch would push me right up the seat until my head nearly hit the roof. So, I spent a few hours with everything I could find to get the "slick" off the seat, and ended up using a rosin bag (baseball) to make the seat sticky. Currently I run a heavy duty disc and pressure plate (custom mod for nailhead) purchased from Fort Wayne Clutch on my Skylark, and with the 2x4 nailhead and pretty heavy cam, and I don't have any trouble with the clutch, and I have done some pretty heavy launches in both 1st and 2nd, as well as hammering from a slow roll, and never had any slipping. I have a hydraulic release bearing, and the pedal is pretty much "normal" feel. I prefer a diaphragm pressure plate over the three finger types. https://fortwayneclutch.com/ I think a either that you have selected are pretty much alike. Anyone else want to advise, and may have more input than I do on clutches, since my recent experience is limited in scope? And get someone to help with the grunt work, no sense putting yourself on the couch for the summer nursing more back damage. Give the delivery driver a couple of cold snacks to put it in the garage.
Hated to "like" this one b/c of your back. Good grief. Another board member I'm very friendly w/ went through this. Sounds awful. Good luck. Great info on the trans.
Thanks for that excellent, helpful info. I want to get this right the first time, so I never have to pull the thing apart again.
Thanks, Dano. I am just grateful it's not kidney stone pain. THAT hurts more, as some of you guys probably know. What's ironic is that I wasn't even lifting anything heavy when I blew this disc out. I was babysitting a 5 month-old for a couple who both have day shift jobs and who just lost their babysitter. I was bending over to put a new diaper on the kid, and suddenly felt that stabbing pain that makes any movement an adventure in agony.
