Buick trans swap...

Seriously thinking about going from the T-14 to a BOP T-350 auto. Trying to get some input on what all is involved besides the x-fer case adapter and drive shaft changes. The trans I'm considering is from an '85 V-8 Cutlass... a rebuild would be a given. I've read thru some posts here, but truthfully am looking for some pics/ lesson's learned and OBTW fab requirements from folks who have actually performed this swap. TIA!!

 

Patrick, that's the shifter I am looking at, wish I could get it without the chrome though... A cooler is a must, and detailed pics of your dad's setup would be awesome! I would (probably) use AA for the adapter and new trans shaft; but any notes or hints would be much appreciated ...

 

Make double darn sure it is in fact a TH-350 and not a 200r4. The 200r4 is an overdrive trans similar but much weaker than a 700r4 and is frequently confused with a TH-350. It came into play about that time. Easy way to tell is the TH-350 has a removeable 4 bolt tailhousing, the 200r4 does not....

 

I'd love to see any and all pics and info, too, as I'm seriously considering putting a th350 behind a newly rebuild buick 350 v8 I just bought to put in my Jeep!! Any specific cooler recommendations?

 

Good to know, Nick. I'm going to look at a trans today...

 

I used a B&M Quicksilver with mine that worked well. I used the novak adapter and had a little trouble with the front drive shaft and the pan wanting to occupy the same space. I had to do a little hammer tapping to make it fit but I think the problem arose from the d44 I used in the front that i think pushed the front end of the front dshaft toward the center a wee bit too much. Over all I like it a lot.

A twin stick conversion would simplify things if you haven't done it yet.

 

So, here's a list of parts required that I've come up with:
Trans, torque converter (stall?), adapter, pilot bushing, flex plate, shifter, trans mount, new F/R drive shafts, cooler.
I'm looking at both Novak and AA for the adapters and misc; the only difference I see is the AA kit comes with a new output shaft where the Novak kit needs to be ordered separately. Looks like minimal fab would be needed (trans mount/ trans cover mod for shifter, cooler mount), but until I've seen pics of a completed conversion I won't know for sure. Anything I'm missing? Preferences on adapter companies, and why?

 

I guess the first step is looking for a trans, although I haven't fully commited to the conversion... Worst that will happen is I'll learn a bit! I wanted to look at one today, but got off work too late and the seller works nights. Aside from what Nickmil posted about the 4 bolt removable tailhousing, anything else I should pay close attention to during the inspection? I was hoping to get one from a drivable vehicle, but this one is already removed...
There's an interesting note on the Novak site: "Note here that automatic transmissions offer the benefit of gearing built into the fluid drive torque converter. One can multiply an automatic transmission's low gear by a factor of 1.5 to 2" Although I do understand what's being said, I'm curious as to the validity...

 

how do you determine the further gear reduction, and what exactly is it based upon? I'm considering building the bop th350 also, for primarily rock crawling and trail riding, and would like as low of gearing as possible. Do I look for as low speed stall converter as possible? How do I figure the gear reduction in addition to the normal 1st gear ratio? I'd like as close to 2 as possible if at all feasible.

 

Here's the Novak link I used, plugging in my data, including the 2.52 first gear ratio of the T-350 multiplied by the 1.5 factor provided in their note... If I do this swap, the crawl ratio will be a bit better than with the T-14.
http://www.novak-adapt.com/knowledge/gearing.htm

 

Still trying to work thru the stall speed... Some of what I've been reading says to select a speed approx 500-750 RPM below the rated peak torque, which for a stock 225 is about 2400 RPM. Does a 1650-1900 stall sound about right?