I made some preliminary measurements of the T5, Supra and 833 Mopar. I will verify these numbers for those who might be considering a 5 speed swap.

Mopar 833 ( A-body version with 5 1/8" front bearing retainer):
front flange to end of tailshaft : 23 1/4"
input shaft : 8 1/2"
case length (w/o tailshaft) : 10 1/2"
tailshaft length : 12 3/4"
case width : 9"

Supra
front flange to end of tailshaft : 21"
input shaft : 7 3/4"
case length (w/o tailshaft) :
case width : 9 1/2"

T5 ('93 Mustang 5.0)
front flange to end of tailshaft : 24 1/4"
input shaft length : 7 1/8"
case width : 9"

The Supra is shortest overall. As the Toyota linkage is internal it will require less space than the 833. You would need an adapter to fit into the Dodge pilot bearing. The Supra 5 speed looks like a good match to me.

Here is what I heard from Castlemaine Rod Shop in AU:

There are two Toyota Supra boxes, one is from the twin cam turbo model which
will take 450hp and these have a 7 1/2" long input shaft. The other one has
a 6 1/2" long input shaft and will only take 200 hp, we make parts for
both. The housing clears the Australian models o.k. and I can't see yours
being any different.
Regards...............Rod


BTW, the non-turbo twin cam U.S. models I've found have the 7 1/2" long input shafts. Possibly these are the same transmission as the 450 hp export model. These are beautiful pieces of work.

Castlemaine Rod Shop makes bellhousings to adapt the Supra transmission to the slant six? Is that right?

I looked at their website, but I couldn't tell for sure. Could you please give me more information? Were you quoted a price?

_________________
'68 Dodge Dart 4dr Sedan

Castlemaine custom builds two types of bell housings for a Supra to Mopar 318/360. One BH type accepts the stronger "turbo" 5 speed. From what I can determine the U.S. spec Supras may all have the 450 HP 5 speed.

They build an "spigot" adaptor for a GM / T5 to slant six, they don't have a bell housing for the slant six to Supra transmission ( or to any other transmission ).

I was quoted a price a several months ago. Because of the varying exchange rates the cost for the small block BH could be favorable to US purchases, although I don't know what shipping charges might be. The total costs would likely be much less than the Kessler small block 5 speed.

Is the '80s Supra transmission the same as the one used on the '93-'97 Supras, or a different design?

_________________
"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

I don't know if the '93 and up transmission is the same, the motor is different. I was told that the M Series Supra motored 2nd generation Supras were available with two types of 5 speeds, one type is stronger.

I believe there was also an optional six speed in the latest series available with a twin turbo motor, but maybe that was only for the export market. I think the Supra is still produced and sold for the overseas market. I'll ask on the Supra groups.

The last series Supra was very expensive(well into the Lexus range), the early Supras are priced like a Japanese Z28. The M Series 3.0 is an undersquare small bore six(3.27bore" x 3.58"stroke) , the later motors are square. I've only pulled transmissions from the "M" series motored cars. These transmissions are similiar in dimensions to a Mustang 5.0 T5 but a little shorter.

I was told the input shaft for the Supra transmission is too short for the stock slant six bell housing. A Ford T5 from a Mustang will be OK. I don't know of a practical work around for a shortened BH to mate the Toyota part. I suppose a steel BH from another type of motor might be modified as it is easier to shorten and reweld those, but lots of work to custom mill and weld a slant six pattern flange.

What is the web address or phone number for Castlemaine?

_________________
Ive got a slanted attitude and a heavy right foot.

Castlemaine : rod@rodshop.com.au

wow, this all sounds exciting guys, and i feel a little late on picking up on this link. but i just went to the castlemaine website and it makes sense that their bellousings seem to place the clutch fork on the right side of the car since their steering wheels and pedals are there too. i suppose a hydraulic setup would make things work, but are there any available for the supra trans? i can't remember how the slave cylinder mounts on those things. i wonder if the mcleod unit would fit?

-james

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The factory Supra slave cylinder is bolted to the outside of the bell housing.

I think the only way that the Supra trans would work with the slant six is a custom bell housing, the Supra is compact -- that's great for saving space, but the input shaft is a little too short, needs a shorter bell housing to work. With a proper BH, I think this might be about 3 inches shorter than the Mopar 833. The compact dimensions ought to allow it to work without floor pan mods.

I've thought of getting a used steel BH designed for some other motor and shortening the length, welding on a slant six BH pattern flange.

tim-
i know it sounds weird but float with me a minute. why not use one of these supra to s/b bellhousings from castlamaine with a slant-s/b 727 adapter plate? i'm pretty sure the starter mounts in the same position. a bit of ingenuity to cobble up a short input adapter and a flywheel spacer would be needed but sounds a little easier on the 'ol noggin and the wallet if those bellhousings are fairly reasonable in comparison to finding a machine shop that would work with you to achieve similar results modifying an existing slant housing.

-james

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James, you may be on target with the slant six to A-100 transmission adaptor. I have one of those iron adaptors in my garage. I don't know if it is safe to extend the flywheel away from the crankshaft flange in the manner in which the automatic flexplate is shifted out by the spacer required by the adaptor.

Machine shops quote about $350 for any modification beyond the trivial job. If I hacked up a modified steel b/h a machinist would probably charge about as much as the Castlemaine b/h to finish machine my custom steel b/h.

I wish a professional machinist with an interest in slant sixes would frequent this site and help some of us out without the high prices that local shops ask ( who usually don't want to do the work and might not fully understand the goals ). I figure that if someone did a dozen conversions the task would become efficient for them, whereas for a local machinist it is a time consuming one-time job.

If I had the basic machine tools I believe I could learn to do some of these types of projects, but I can't afford the investment. My neighbor was a shop manager who said they paid someone to haul off their Bridgeport mill when the shop closed, he said it was rarely used and in good shape, it was hauled away by a scrap metal dealer just to get rid of it.