T56 Swap to T56 Magnum

[Nitrous]

I have a 69 Camaro that was an original 350 with an auto. The previous owner took all of that out and dropped in a h/c/i LS1 with a T56. The engine is making 475hp and I have plans to add a power adder (supercharger or TT) in the next couple years to push it to 750+. The T56 in it now needs a rebuild, reverse is now almost completely shot and I can't shift above 5k rpm. I'm thinking I might swap it out for a T56 Magnum and sell this t56 as one to be rebuilt if anyone wants it.

My question is, I know that the driveshaft will have to be shortened but will I need to do any other modifications? Will the transmission cross member have to be replaced with a different one? Will the shifter be in the same location or will I need something to adjust it? Will the transmission tunnel have to be modified?

Any help would be appreciated.

[MarkM66]

Have you looked into having your existing transmission upgraded to handle the extra power?

http://www.rsgear.com/

[Nitrous]

Originally Posted by MarkM66

Have you looked into having your existing transmission upgraded to handle the extra power?

http://www.rsgear.com/

There are soo many options out there and every time I ask someone I get a different opinion. My concern with the existing transmission isn't just handling the extra power but being able to slam it in gears at 7k rpm and not have to worry about it going into gear. That seems to be a more common problem in a t56 than the t56 magnum/tr6060.

[Vince@Meanstreets]

Originally Posted by Nitrous

There are soo many options out there and every time I ask someone I get a different opinion. My concern with the existing transmission isn't just handling the extra power but being able to slam it in gears at 7k rpm and not have to worry about it going into gear. That seems to be a more common problem in a t56 than the t56 magnum/tr6060.

The Magnums are just a superior transmission. Better shifting, gears.

The Mags are longer and a bit wider, height is close. The shifters are different but the stick comes out the same, but that depends on the shifter and stick you use.

I would look at what you have now and see what is close. If its close now, the Mag will most likely hit.

You will need a shorter driveshaft and a different trans yoke.

[andrewb70]

RPM Transmissions offer direct bolt in Magnums in place where a F-body T56 used to live. The only thing you will have to do is change the slip yoke on your driveshaft.

http://www.rpmtransmissions.com/page11.html

Also look like you can send in your T56 core for a discount.

Andrew

[Nitrous]

Originally Posted by andrewb70

RPM Transmissions offer direct bolt in Magnums in place where a F-body T56 used to live. The only thing you will have to do is change the slip yoke on your driveshaft.

http://www.rpmtransmissions.com/page11.html

Also look like you can send in your T56 core for a discount.

Andrew

Perhaps I should contact them and find out what makes it a direct bolt in. Their description just states that it's basically a t56 magnum that has had some work done on it but that wouldn't change any of the outer dimensions of the transmission and it doesn't say anything on if it needs a different transmission mount or anything like that.

[71RS/SS396]

Call Bowler and see what your options are. I'm not sure I would even trust a stock magnum at the power level you're looking at.

[gnx7]

I sell T56 Magnums and for the most part you need to shorten your driveshaft and add a 31 spline yoke. The VSS pigtail is different and if you are not running a mechanical speedo you need a plug to seal up the port in the trans (T56 Magnum offers mechanical and VSS style speedo outputs). You can modifiy the shifter to get the desired setback quite easily.... or plunk down $300-500 for an aftermarket one.

The 1-4 ratios stay the same... .80 5th is great as you stay in your powerband unlike the .75 factory T56 ratio which is rather tall. The smoothness in shifting is no comparison. I have shifted them as high as 7800rpm in my turbo LS9 RX-7 without issue. It's also putting down 1200rwhp+ thru a 100% stock unit without issue. Car runs 9.30's@163mph launching with zero boost and not powershifting. I have the T56 Magnum also in my LS7 RX-7 and it was a very noticeable upgrade over the previous rebuilt T56 it had. If you don't plan to drag race a standard 31 spline yoke is fine. If you do plan to really beat on it... get a billet yoke. I run McLeod twin discs in all my cars and they work/drive great with super low pedal effort and non grabby uptake.