I'm building a 29 model A sedan with a SBC and could use some advice on selecting a T-5 transmission. Flat Ernie wrote a great post some time ago which I have read, but I still have some questions. Based on Flat Ernie's post it seems a t-5 from a camero/firebird with a tailhousing from a S10 is the best combination for gear ratio and shifter placement. After reading Flat Ernie's post I went back to the magazine library and read a couple of articles with rods that used T-5's and in all cases the articles say they were from S10's which would mean either the articles were not correct or the S10 gear ratio can work in some applications I am a little dense when it comes to gear ratios so I need some help. What gear ratios should I be looking for? Also, is it important to find a world class unit vs a non world class. Thanks for your help.
There is a whole list of available ratios depending on the original application so I'd suggest matching the gearset to your power output and make sure you select an application with the best OD ratio. Alot of people I know run "non-world class" T-5 with a great deal of success. If you are going to beat on it, better go "world class". Flat Ernie has everything listed you need in that great tech post of his but to shop for a trans you need to have a print copy of the trans I.D. numbers/application & ratios chart.
The input shaft length on the V6 (S10) transmissions is about 1/25 inches longer than the input shaft on a V8 (Camaro, 'Vette) transmission. I ended up buying a T-5 out of an Astro van for core price, dumped most of the guts and replaced them with new V8 pieces from Tremec. I ended up with a nice tranny for about $800. The shifter location on the Astro is almost exactly in the middle of the tail shaft putting it perfectly in front of my seat position wise...
The reason most folks use the S10 as-is is because they either don't care about ratios, changed their rear ratio to accomodate the trans ratios, or are not confident enough to change the gears out or swap tailshafts/topcovers out. CB Chief - the Astrovan gearset isn't all that bad - certainly better than the S10. What did you use for a shifter? Astrovan had a remote shifter. I have always guessed that a GM shifter (S10 or Camaro) would probably bolt on where the remote thing did...is that what you used?
Thanks. I guess I need some 101 on gear ratios. The car is currently set up with a rear end from a 57 chevy with 3.55 gears. I do have plans to swap this out at some point with a quick change. What transmission ratios would work best with a 3.55? I am running a SBC with roughly 350hp. Thanks for your help.
rockman, what tire size are you planning on running and what are you planning on doing with the car? Daily driver, weekend cruiser, 1/4 mile blasts... it all figures into the ratio you want.
The car will be used on the weekends for cruising, which will also include scaring old ladys and burning the rear tires off . Rear tire size will be Firestone 750 -16.
750-16 with a 350 Chevy? Tires won't bite enough to worry about breaking anything. Gear ratio won't matter that much either. 3:55 is a decent all around gear.
Keep the 3.55 and look for a trans with the 3.50 or 3.76 first and the 0.72 or 0.73 5th. Some of the others have a lower first gear (4.03) which would be useless in your light car (unless your pulling stumps) with the 350 and tires you want. Or go with a Tremec Model 1st 2nd 3rd 4th 5th 6th HP Torque TKO-500 3.27 1.98 1.34 1.00 .68 n/a 550 500 ft/lbs. *(Wide ratio & Street OD)
I used a shifter off an S10. It bolted on fine but the shift mechanisim is a little looser than I like. It had one of those chrome screw on shift levers that I threw away. I cut the rod sticking up out of the shifter plate off and welded a Hurst "Indy" shift lever to it. It looks good and works nicely also. I will go home and take a couple of picture this evening and post them tomorrow. Larry CB_Chief
Thanks for all the great info. The car is being built with a traditional look, I know the SBC doesn't exactly fit that bill but it's what I got , it came with the car and it's new engine. Obviously a souped up flathead would be prefered but that will have to be another project. I actually like the pulling stumps comment. Maybe I can tell my wife it's a yard tractor when she asks where the money's going . CB Cheif, I'd like to see photos of the shifter if you have them. Thanks
Another thing to keep in mind is the speedo. S10 T5's are either mech. or electric, and you can't swap them without changing the tail housing. Technically, the tailshafts are different as well, but workable. So get the right one the first time. It is possible to use the later electric versions with a mech. speedo, but it will cost you about $300 to do it. I believe Bowtie overdrives sells the "box" that does this. As said, the 3.50 or 3.76 first gear would be ideal. The're a little harder to find in an S10, but I believe the V6 Camaros used them more. Of course the shifter may be an issue then. S10 versions need to have the input shortened 1/2" and the collar needs to be shortened as well. Test fit the clutch disc and tranny to make sure it will be able to disengage the flywheel. If it doesn't, you'll need to either grind the hub splines, lengthen the shaft splines, or add a spacer between the tranny and bellhousing. I have run both the 4.03 and 2.95 versions behind my 261 L6 with 3.55 gears and 235/75 R15 tires, and while the 4.03 is a little short, its not as bad as some would have you believe. The 2.95 is actually a little tall, so I may change to a 3.70 rearend. Of course, this is in a truck that hooks up, it doesn't "lite 'em up". Zumbrota Bearing and Gear has been real good to me on pricing and availability of T5 parts. To make a short throw shifter, take your stock one apart, press the pin out of the shift lever, drill new hole about 1" higher and reinstall the pin. Reassemble shifter. Then make a spacer plate the same thickness as what you moved the pin. This will shorten the shift throw a little less then half.
Astrovan versions are hard to come by, and I've never seen one up close, so no, I can't say if it is or not. Craig at Zumbrota should be able to tell you, I should think. Why are you worried about it?
All V6 engine application T5s have longer tailshafts from what I have seen. I went through a pile (40-50) of T5s looking for the exact one I wanted and only found one Astro van model.
Not really worried, in general I'll take on most tasks assuming I have the right tools, can borrow or can afford to buy the right tools, and there is enough technical info available to get me thru it. How difficult is it to shorten the input shaft of the S10 trans? Thanks for all the info.
I swapped a 302 into a Ford Ranger p/u in the late eighties and had to shorten the input shaft, I just used a cutting wheel on an angle grinder. It worked fine.
http://www.btc-bci.com/~billben/flathead.htm Check out this site. Go towards the bottom & there are two threads about T-5 swaps. A lot of useful information on raitos, years made, etc. Good luck. I think I'm going to go this route with a flathead powered roadster as well. Tim
When I shortened mine I just used a cutoff wheel in my 4 1/2" grinder. Just take it a little at a time, you don't want to turn the whole end blue. Also, give it a little chamfer so it goes back in easier. Wrap a rag around the collar end, so you don't get crap inside. To shorten the collar, you'll want to take it off, and use the same cutoff wheel. Deburr, clean, and reinstall. Don't loose the bearing race or its shims, while you're at it.
Thanks for the helpful information Snarl. That sounds pretty staight forward. I have a couple of leads on some S10 T-5's locally that I'm going to check out this weekend. Thanks to everyone who provided info.
The Astrovan input is same as S10 & Camaro as far as I know... I've got a gearset from an Astrovan, but not a complete tranny (ie - no tailshaft). Got an S10 case & Jeep output shaft & tailshaft housing - going to adapt it all to closed driveline eventually. Gotta love the Frankenstein T5 And I'm fairly sure you can swap any OD ratio into any trans - the only two gears that matter on 5th are both removeable & on the outside of the main case...
I am not sure of the Astrovan input shaft, but the S-10 and the Camaro have different spline counts. The S-10 (4/6 cyl.) being 14 and the Camaro (8 cyl.) is 26. They are also different diameters, 1" S-10 and 1.125" Camaro. I would imagine that the Astrovan input shaft would be the same as the S-10.
"I would imagine that the Astrovan input shaft would be the same as the S-10.". It's the same 1" -14 spline as S-10, but the length is the same as the V8 Chevy T5, and the 60º V6 F body T5. I just put a V6 F body T5 behind a 90º V6 by using the Astrovan clutch and flywheel. The input shaft does not have to be modified like the S-10 version does. Bob
I'm putting a Camaro t-5 behind the 230 that is in the wife 62 Chey II. I have the V6 version with the 4.03 first gear, this will go nicely with the 2.41 gears that the rear end has. I'm using the stock pressure plate, but the Camaro disc, both 9 1/8". It think the these trans have gotten a bad rap, for a L6/flathead v8 I do not think that they could be beat. This seems to be one of the most adaptable trans out there.
Sorry - should have been more clear - Length of input shaft is the same as S10/Camaro...still gotta pick your clutch to match the shaft diameter & spline count as you pointed out.
Ernie, Things fell apart last night (kid came in from out of town). Sorry for the delay, I will take pics and get them on tonight. Larry CB_Chief
I thought most of the 4.03 low gear transmissions had the almost useless .83 overdrive ratio in 5th?? I could be wrong but it would be better than a trans with no OD (1:1).
Yes - most have the lowest OD ratio. OD ratios can be swapped very easily - both gears are removeable from the shafts & are in the tailhousing. You can bolt a .68 OD onto one of the .83 trannys...
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