Shortstar trannys

[gobigorgohome]

ive got a oldsmobile intrigue shortstar 3.5L, i have 2 TF904 trannys one with a fresh rebuild so id like to use them. having some issues drilling out the flywheel for the torque conv, i would like to run the TF trannys just wondering if something like a TH350 or 400, TF999 or any other tranny would bolt right up and how many bolts the Torque conv are? is there any tother tranny options ?

[Klasick68]

I'm assuming the 904 is from an XJ with a 2.8 (IIRC the shortstar is GM 60degree bell right?) I would be tempted to try the flexplate for an XJ with a 2.8, but I know nothing of the balancing of the shortstar (2.8 is ext balanced), so even if the flexplate bolts up you will more than likely need to have it rebalanced. Hope that helps ya some

[Shaffers Offroad]

the TF 904 out of the 2.8l xj is a direct bolt up as far as the bellhousing goes, but you will need to drill the flexplate for the 4 bolt converter. you will also have to cut a releif in the left side of the bellhousing for the starter. Make sure when you cut it out, that you weld a piece of aluminum around the releif to add strength back into the bellhousing or it WILL crack!!!

the 700r4 out of a 2.8l S-10 is also a direct fit with no bellhousing mod's required.

there's also an adapter made that allows you to bolt any 90 degree GM bellhousing tranny to the shortstar, i have one sitting on the shelf here at the shop that we had ordered for a project a while back, and then the buildup plan changed.

[mondtster]

Originally Posted by Shaffers Offroad

the 700r4 out of a 2.8l S-10 is also a direct fit with no bellhousing mod's required.

there's also an adapter made that allows you to bolt any 90 degree GM bellhousing tranny to the shortstar, i have one sitting on the shelf here at the shop that we had ordered for a project a while back, and then the buildup plan changed.

I'm using a 60 degree 700r4 behind my cadillac 4.9L motor. There is only 1/4" difference between the s-10 torque converter bolt pattern and the Cadillac flexplate. Unfortunately, I have no idea if the shortstar or northstar flexplates are that close to the same dimensions or not. The 700r4 might be an option for you though.

As for the 904 converter and the shortstar flexplate, I would suggest having a custom converter made to match the shortstar flexplate mounting pattern if you don't want to try and drill holes. There are plenty of places that should be able to rebuild a converter the way you want it. I would just give one a call and discuss it with them.

[gobigorgohome]

i am getting the flexplate drilled out right now, but machine shop is going to have to tach on washers to the TorqConv lugs so that it will clear the rivets on the flywheel. so you guys are saying that a turbo400 will bolt right up with that adapter (who makes it)? and will the TorqConv bolt right up to the 3 hole flywheel on the shortstar, if it does i would rather go with that instead of notching out my case wich i was also about to do.

[mondtster]

I think that the 60 degree 700r4 from an s-10 is by far the closest thing to being 100% bolt up without the need for extensive modifications to the case or special adapters. As I mentioned before, the only requirement for my cadillac 4.9 flexplate is to file out the 3 mounting holes slightly. I'm planning on doing it in the next couple of weeks and mating the motor and trans together shortly afterwards.

I also have a tf904 with the 60 degree bellhousing bolt pattern on it as well. I was seriously considering using it, but elected to go with the 700r4 for the lower 1st gear and ease of installation.

Both the 700r4 and the 904 are good trannys and can be built to take whatever kind of power a shortstar can give them. I don't see any need to switch to a th400 unless you already have one and don't mind spending money on the adapters (which could be made as well).

I have no idea on what or where to get that adapter kit to use a normal 90 degree GM tranny behind a 60 degree motor. I wonder how complete the kit is?

[gobigorgohome]

i do have 2 TF904 one witha fresh rebuild so ill trty drilling this flexplate out first and go from there.

[Shaffers Offroad]

Originally Posted by gobigorgohome

i am getting the flexplate drilled out right now, but machine shop is going to have to tach on washers to the TorqConv lugs so that it will clear the rivets on the flywheel. so you guys are saying that a turbo400 will bolt right up with that adapter (who makes it)? and will the TorqConv bolt right up to the 3 hole flywheel on the shortstar, if it does i would rather go with that instead of notching out my case wich i was also about to do.

Jason Scherer's Diablo1 ran a TF904 behind a SS and was built in 03, and is still running that combo today with it's new owner, flex palte drilled to match the 4 bolt pattern no issues. DSI's last 2 buggies have ran that TF904 with re-drilled flexplate's with no issues totaling 4 years of use.

We have the adapter plate here at the shop to use a 90 degree bellhousing on a 60 degree bolck, it's only $75, it's the plate and a few bolt's. very simple kit.