So I saw on here that gforce makes a t5 case for $400 that makes it be able to with stand good power. Has anyone done this or can confirm this? I'm building a. 350 with roughly 450 horsepower. I know I would have to upgrade the gears and main shaft too. But I'm just wondering about the case. And in fact how much power can you put to factory gears and main shaft?

The stock ones grenade at 190hp, I doubt even a beefed up version would last at 450hp. T-56 or stick with auto.

As much trouble as you've had w your T-5 over the years, prolly best to not throw MORE good money after bad.

By the time you do all that crap to your T-5, you'll have T-56 money in it, but you'll still only have ... a T-5. Unless you're racing in a sanctioned class with rules that require a T-5, best to cut your losses and move on.

T-56 time.

Lol you remember all the troubles. And the reason I was thinking of this route was so I wouldn't have to convert everything over to ls1 or lt1 and have all that money tied up. And the trans is doing good now. Just can't take power. Lol had a buddy professional rebuild it(at a nice discount of course) turns out when I did the rebuild I didn't have enough preload. Dam shims, always messing me up. Lol. But anyways. I understand your point but do you see where I'm coming from and why I was thinking this way? I'm fine by a 5 speed just this way I don't have all the conversion costs from the t56 and ls1 plus it's cheaper to build up the 350 to my goal of 450hp.

An Lt1 T56 is your best bet. You can get a complete swap for around $1500, sell your T5 stuff for around $5-600. Think of the cost you would have into your T5 after you are done... The $400 case, the labor to swap cases and everything. I think it would be cheaper to just go T56.

400 for the case. 1200 for the gears. 150 for labor. Still coming out cheaper then if I find a lt1 t56 plus 200 for the cross member and... Can I use a lt1 t56 bell houseing on a 350?

Going by the numbers you posted, you'd be spending about the same amount of money either way. If you find an LT1 T56, it'll bolt up fine to a SBC, and will probably hold together better than a "beefed up" T5.

That I'm sure of. Hmm forgot the lt1 t56 bolts to sbc. And I could sell the t5 get money back I suppose. But I would have to luck out and find the lt1 t56 and have the money at the same time. Where as beefing up the t5 I can gradually do. Lol back to the oringal question will the gforce case and gears handle the 450hp?

$275 for the case is what gforce quoted me a few weeks ago. About the same price as a good used t56.


According to gforce it can hold 600

Even cheaper he'll yay. I think I will just stay with the t5 simply for the fact I never have the 1500 at once when a t56 does finally show up.

You know my take on this Between posts and PMs. LOL

The main thing about cases is the front two bores that fit the bearing races will eventually expand out of round. So it's a 100,000 mile maintenance item. If you were in4th gear all the time, they would go 200,000

The loose mainshaft pilot rollers don't hold 3rd speed and countershaft gears at a consistent distance under power.

And 5th isn't supported well at the back of the countershaft.

If you can build it, you can drive, and you don't care for more ratio options, go for it.

For your planned power level, I would aim for selling the T5 and moving on.

I'm still not finding used T56s under $1200, even the Pick-N-Pull yards are taking them before putting the '93-up Z28s out for the public. If you can get one for $275, then sell it to me for $350 plus shipping.

Same around here, your not finding a t56 in the yard. I picked mine up few years back for 700 with bellhousing and fork at swap meet. I lucked out at that price I think. As everyone else said Go t56 and don't look back.

If you aren't planning a lot of hard launches the T5 (stock case) with Gforce internals will hold better than stock. I went with a TKO 600 but by the time you get the trans, bell and all it's $3 grand. There is an aftermarket T56 that is a retrofit. I think all of the T56's will require some cross member and maybe torque arm considerations. Any way you go a good strong stick shift costs a few bucks. I still go through clutches and a good one is $5-700+.

Then you gotta consider the rear end if you gonna really put the wood to it out of the hole with traction. That's my next step.

A built auto is hard to beat for reliability and consistency but shifting gears is fun too. It's really about what you want to do but any route is gonna cost money.

Retrofit t56 isnt a better option at all for us... Depends.. .You need at least a custom driveshaft and a further altered shifter location to make those work.

??? I have a T56 in my GTA and the stock driveshaft fit fine. Also, the shifter isn't that far from stock.

With a TKO 600 (and I presume the 500) the shifter location is less than ideal. I don't think there is a shifter handle available that will work. With the TKO shifter in the rear-most location it ends up directly under the ash tray. In fact, I shortened my ashtray about 1/4" just to provide clearance and made a custom shifter handle that positioned the **** in approximately the "stock" location. It looks factory with the boot on but underneath it is shaped like a crescent moon with a bracket on the end. It took a couple of tries to get a satisfactory result. That along with some "clearancing of the trans tunnel and I went ahead and had a driveshaft made that was 1" longer even though the stock length would have worked but I didn't like the yoke hanging out so far. I may be wrong and there may be comprehensive kits out there but any trans that wasn't factory is likely to take some fabrication. That is the reason the Gforce T5 is an attractive option. It's not as strong as some other options but it does bolt right in.

I also have a T-56 in my 83; a Hurst shifter; fits PERFECT. The stock **** even fits on it. I got the block shifter handle: if you don't KNOW it's been changed, you can't TELL.

Same for the drive shaft. Fits perfect.

Only modification I had to do, besides getting a different crossmember, was to elongate the shifter hole about an inch toward the rear, because the T-56 shifter pad is longer that way for some reason and is taller, so it sticks up into the car interior slightly.

94-97 Z28 or Trans Am is the source for the right T-56.

Never messed with the aftermarket versions of the same basic transmission design, from the same company, marketed as "TKO"; didn't have to. Just got one at the junkyard. Granted they're getting tougher to find nowadays as the early 4th gens are now also almost ANTIQUES, but they're still out there.

You guys are misunderstanding. You've had your T56's too long to remember what you find when you research various resources on doing the swap.

He is most likely referring to this, or some copy of this information somewhere else:

http://www.skulte.com/T56.html

"Retrofit T56
The major benefit to the Retrofit T56 is that it allows you to use a standard style clutch and bellhousing. It also has a mechanical speedometer sender which is similar to the 700R4 & T5 transmission (an electric 700R4 & T5 VSS will bolt right in). The draw backs are that the transmission is 1.9" longer, so the driveshaft and torque arm must be shortened. It is available new from Tom Sallee at Sallee Chevrolet for $2295. "

Hence my response:

I've never seen one or heard of anyone actually having one, but my point is for our cars a regular LT1 T56 is actually a lot easier to work with. It's essentially bolt in.

Discontinued quite a while ago; probably 10 years or better. Dyno Don on here has mentioned his.