Just thinking about putting a T350 behind the 330 in my 65 Cutlass. The ST300 is/was still functioning when I pulled the motor and trans last fall for some clean up and detailing. However, I just wondered what is involved in switching to the T350? Will a T350 torque convertor bolt up to the 330 flex plate? If not, what flex plate will work? Does the trans x-member have to be relocated? Can the stock console shifter operate the 3 speed trans? What else must I consider?
I have an "extra" Olds T350 sitting in my shop that also worked fine when it was removed from a previous project and replaced with a T400. The T350 is cetainly more common than the ST300, and I have read several posts on how the variable vane function can end up being a problem. What do my fellow classicoldsmobile members have to say?

 

From my understanding it's just a bolt in. The drive line should work and the three speed will work if your colum has some slop in it you might be able to access first gear.

Not sure on the flex plate tho I do know that the 330 flex plates are different than the 350 on the crank pattern

 

You mentioned a console, so you've got the floor shifter. I think you'll need to replace or modify the detent for the additional gear selection. Here's a link to an aftermarket kit with the detent, new cable to replace the rod and other pieces to install the 3 speed or even a 4 speed automatic if you chose. I've not personally used their products but have heard from others that they were happy with them. John

http://shiftworks.com/cutlas.htm

 

yep, but the torque converter bolt pattern is the same so no issues with the TH350 swap.

 

Thanks for the replys guys! It's great to know that a T350 torque converter will bolt to the 330 flex plate. That shifter modification kit is neat too. The Summit catalog shows (2) different bolt circle dimensions for T350 torque conveters, 10.750" and 11.500". I will have to see which one of the two matches the 330 flex plate bolt circle. Perhaps I will get lucky and the converter I still have will be the right one.

 

As noted, the TH350 has the same external dimensions as the ST300, so it bolts right in with no changes. The only small issue is the need to run a kickdown cable. Since Olds never used a TH350 in the 64-67 cars, you'll likely need to adapt something aftermarket.