T5 to lsx
 

I'm looking to mate a stick to a stock 5.3 and I'm trying to do it CHEAP, which means staying away from the T56.

Yes, I know the T5 is weak, but this car won't be abused. It'll be a DD. No track runs.

I'm trying to figure out the total cost of adaptation vs picking up an LS1 T56, which the cheapest ones I have found are around 1000 bucks.

Any input appreciated.

Re: T5 to lsx
 

Your going to need a custom flywheel, and likely clutch disc to work with the T5 slave, then your going to loose some mounting lugs.

By the time you do it all, you could have had a T56 and it would be FAR stronger.

Not worth it at all due to cost, and 0 gain, as the trans wont last more then a week behind even a 5.3L which in truck outfit with a stock exhaust is 295hp

Re: T5 to lsx
 

I heard a one peice RMS flywheel would work. Could you tell me the difference? I know it will be missing a bellhousing bolt. Everyone does when they mount a th350 to an LS1.

The trans would last as long as I make it last. Its all how you drive. The average 305 was 300 ft/lbs, the 5.3 is 325 ft/lbs. The car is also only 3000 lbs. I've seen many T5s live behind high hp, damage happens when you side step. It just takes a little self control. And if it does break, oh well I throw another one in for 50 bucks.

If I could pick up a T5 for a hundred bucks, and the adapting hardware only cost me 300 bucks, it would be worth it to me.

Re: T5 to lsx
 

A stock T5 won't hold up very long behind it, I knew a guy who had a WC-T5 behind an LT1 and blew it up 3 times before he decided to put the T56 back in the car and it has survived all the abuse he put to it. People buy adapter plates to use a flexplate for a TH350 which you probably could use a T5 from a Z28, but T56 are getting reasonable in price.

Re: T5 to lsx
 

Well so far I've found out that I can use an LS7 pilot bearing, LSX clutch and flywheel, and bbc bellhousing to house the clutch.

I think a t5 WILL last. Its all how you drive it. The motor only makes 25 more ft lbs than the cars it came in, and it will be getting shifted nicely. My buddy has been using a 4 cylinder T5 in his mustang for a year and a half and only broke it when he downshifted from 5th to 3rd a couple days ago. He shifted much nicer than the prior 11 T5s. He makes about 350-400hp.

Re: T5 to lsx
 

Don't be another guy that insists on learning the hard way.


Whats the point of having power if you cant use it?

Re: T5 to lsx
 

Well, hopefully you're right, but it's a fair bit of work & cash to be betting against the odds... Best of luck with it.

Re: T5 to lsx
 

If you are gonna daily drive it and just putt around town, sure it will be fine. But what is the point in putting a five speed manual in your car and have all that power if your aren't gonna use it? May as well swap the 305 back in as well.

Re: T5 to lsx
 

Well I can hammer the gas once its in gear, its smacking gears that are rough on em. The truck is going to have a weak rear as well, and it won't get much traction anyway unless I use some real big sticky tires.

Its an S10. It won't take any abuse to get it going.

If I can pick up a used LSX flywheel, clutch, T5, and a BBC bellhousing (to house the 14" flywheel) for under 500 bucks, I think its worth it. I could even ignore the clutch and flywheel since most T56's don't come with that anyway.

If I could find an LS1 T56 for under a grand, I would go that route, but the goal of this project is fun, quick, and cheap. Quick and cheap CAN live together under the same roof.

Re: T5 to lsx
 

Well, you won't be using an LSx clutch, the splines are different on the input shafts for sure, and the slave cylinder setup is totally different. You won't need to use a BBC bellhousing, just use a normal clutch setup for a T5 and you should be fine.

and...I have never seen quick and cheap live under the same roof and survive very long.

Re: T5 to lsx
 

Thats what I'm being told by a guy that mated a richmond to a 6.0. 1 1/8 x 26 spline.

So you're saying that a sbc flywheel will bolt to an LSX crank?

Re: T5 to lsx
 

You might want to look at D&D Performance, see if they have any info about putting a T5 behind an LS series motor.

I'll have to admit I didn't look carefully at the crank when I installed the LS7 flywheel and clutch, and don't have the original flywheel around anymore.

If the Gen I/II flywheel will bolt to the LSx crank (and, I don't know if that's the case), LSx flywheels are neutral balanced while Gen I/II flywheels are weighted to take the place of the counterweight that was external to the rear main seal on 2-piece RMS engines. So, if a 1-piece RMS Gen I/II flywheel actually bolts on, it will have to be rebalanced first.

I think. . .

Re: T5 to lsx
 

If it does bolt up, couldn't I just use a pre 87' flywheel? IIRC, they don't have any weights.

Completely different flange and bolt pattern.

Re: T5 to lsx
 

1 piece RMS vs 2 peice?

Right.

Re: T5 to lsx
 

If you are interested, I have a never used LSX flywheel for sale. PM for the details, I'm not looking for much.

Re: T5 to lsx
 

Subscribing to this one . . . :nod:

Re: T5 to lsx
 

It seems there is more demand for this than I thought.

http://cgi.ebay.com/ebaymotors/LS1-L...Q5fAccessories

Re: T5 to lsx
 

385 bucks. I'm planning on picking up used lsx stuff. Found a flywheel, clutch and plate, ls7 bearing, and a bbc bellhousing for $300.

12" clutch, meaning 14" flywheel. Won't fit in a T5 bellhousing.

Personally, I can see only trouble ahead for this marriage. I'd stick with a good ol' T56. More than likely it would end up costing less in the end, and you'd have a better transmission.

Re: T5 to lsx
 

Yea, I was wondering about that. I don't know if thats what they meant, it said it would fit in any sbc or bbc bellhousing.

I don't see why a T5 couldn't handle 300hp and 325 ft/lbs. They are rated for 300 aren't they? With a soft clutch, street tires, and little abuse, why not?

I think I could get a T5 in for under 500 bucks vs 1200 for a T56. The T5 would need a shorter driveshaft, which I'm not exactly sure would cost. The T56 wouldn't...

I may be giving up on this idea though and just sticking a T56 in my blown camaro. That would satisfy my desire for some stick. :lol:

I'm dying to build something with a 5.3 and a T5 though. Something light........

Re: T5 to lsx
 

If people are blowing up T5's behind a stock 305 TPI motor, I doubt it would last very long behind a 5.3 or LS1, hell I know people who blow up stock T56s behind LS1's

Re: T5 to lsx
 

I'd like to know how they were being driven at the time though. A T5 could break behind a 4 cylinder if beaten enough.

Re: T5 to lsx
 

My big question is isn't the cranckshaft flang a different distance from the bellhowsing flang between the ls and the gen1 engines. So you would need a special flywheel like the one linked or the clutch wouldn't be in the right location. Same reason you can't use a lt1 t56.

Re: T5 to lsx
 

I think its just the length of the input shaft. The lsx is longer, the lt1 is shorter. The lsx has two bearing journals, one for its stick trannies, and the larger one for the tq converter hub. The ls7 pilot bearing sits in the tq converter journal, and this accepts a gen 1 input shaft. I hope I'm using the term journal correctly here.

Re: T5 to lsx
 

Just thought I'd revive this old, old thread and say that if I could find a T56 anywhere these days for as much as you guys say they go for, id take it in a heartbeat.

They don't go for under 2800 these days, and that's LOW.

Re: T5 to lsx
 

Everything has gotten more expensive in the last 10 years since this thread. But would think T56 prices are going down now that you can buy a brand new Magnum F for $3,400.

Re: T5 to lsx
 

I used Texas Drivetrain Performance to upgrade and convert an LT T56 to a stage 2 LS T56. They did good work, and I think they sometimes sell rebuilt T56's. I briefly read through some of their facebook posts. Looks like the owner is dipping his toe into the T5 upgrade market. I know you want cheap, but finding out a used tranny is trashed after you install it would really suck.
https://www.facebook.com/TexasDrivetrainPerformance/

621 bell housing
 

I ordered a 621 bell housing and now am realizing there is no chance it’s bolting to my t5. It’s a 98 firebird with a 3.8 and a 5 speed so I thought it was a t5. I see this thread is old, but has some recent activity. Any help would be appreciated!

Re: 621 bell housing
 

Help with what? you didn't ask a question

Re: 621 bell housing
 

what bell housing I’m supposed to get if the 621 dosent bolt to the t5, or what I should do because I’m completely lost

Or maybe I don’t have a t5 and I’m just an idiot

Re: T5 to lsx
 

621 bellhousings were for old 4 speeds as I recall. I'm not sure what you're trying to do but the only 5 speed it might bolt to is a tko and I'm not 100% sure on that without researching

Re: T5 to lsx
 

The 621 is for an old 4 speed or for a T56 with the adapter bellhousing. I don't know what T5 you have, but if its 84-92 F-body then you need a T5 bellhousing

Re: 621 bell housing
 

advanced adapters makes a aluminum bellhousing that will take the ford/jeep bolt pattern T5. If you got a normal 621 it’s the older GM style bolt pattern. Here is a link to the adapter on Amazon. https://amzn.to/3F4M3br

Re: 621 bell housing
 

621 should work to bolt a gm t5 to a ls and use a 11" clutch setup. Checkout my build where I did it with a 4th gen t5 which was a little more complicated (has a ford bolt pattern).

Re: T5 to lsx
 

Keep in mind everything that connects to the transmission will be out of alignment. The cross member, trq arm, shifter, etc. They all have to be adjusted to account for the straight up installation.

Re: T5 to lsx
 

That was a cool build thread, 3100chevy. Since you’re in Canada and seem to have a large source of car parts, I couldn’t help but think of that show Rust Valley Restorers.

This write-up had some good info. 4th gen T5 won’t work with 621.

https://www.corral.net/threads/lsx-t5-the-final-word.1744385/

Re: T5 to lsx
 

Hah, sounds like me. Did the LT1 swap and kept the T5 for a while. It lasted well enough, I also hammered the hell out of the car, and then did an LT4 topend and beat on it some more. After the 2nd rebuild I finally did the T56 swap. A T5 behind a 5.3 would be fine, especially for just a daily driver. Can't help on the parts, but you'll for sure have to come up with a speed sensor solution for the 5.3 PCM. That was the main issue I had with the T5 behind the LT1.


*ETA: Holy thread necro. Totally missed the original post date :lol:

Re: T5 to lsx
 

Referring to the beginning of this thread. I had a 87 GTA that got wrecked. It had TFS heads, Lingenfelter 219 cam, accel intake, etc. It cracked the intake when it got wrecked somehow. So I put on a Performer carb intake and a Holley. Stuck it in a 84 Z28 with a T5. It broke the T5 doing a burnout. Without powerbraking on reg street tires. Not even Z rated street tires. Not even V rated. Lol So as stated several times above. Just do it right the first time. The added insurance is worth the little extra cost. Just my 2 cents.