When I rebuilt my '65 Skylark about 9 years ago, I had the ST300 rebuilt. I have had the tranny back in the shop several times to reseal it up. Right now it is leaking from the front, from the rear, and from both sides. I'm about ready to give up on the ST300. The car has only gone about 5,000 miles since the rebuild. What is the best tranny to replace it with? I currently have the high compression 300 V8 and am very happy with it. I also have a rebuilt rear end with a limited slip rearend and 355 gear ratio. I have heard about 3 speed autos and overdrive trannys from newer cars. Which one would be best suited to my application? What is needed to bolt it up to my engine? Does the driveshaft need to be changed or altered? What about the shift pattern at the floor/console shifter? Please don't suggest getting rid of the engine. That won't be happening. Thanks in advance. Greg
Leave the 300 right where it is. The 400's are the best by far. But, the 300 in front of a 200 4 speed wouldn't require any expensive mode and would probably last theblife of your car. That being said, I'd recommend the 400 anyways. Just have had nothing but great realiabilty and performance. Never disappointed me.
I was going to run a 200R4 behind at 300 at one time,,,,I ended up getting one from an 87 Monte SS,,,,,but the best ones are from the Grand National cars!!!! The 200R4 has a dual bolt pattern so it'll bolt up to your engine no problem,,,,there are a few guys on here who have done it,,,or know more about it than I do,,,,hope one of them will chime in with more info!!!
What 300/400 are you talking about Joe?? The 200R4 usually come with 2 bolt patterns,,,the chevy deal,,,and then an olds/pontiac/buick set up!!! If your talking the 300 V8 verses the 401 Nailhead,,,they're different bell housings!!! The later 400 buick engine will bolt up the same as a 300 as far as I know!!!
Both the THM-350 and the 200r4 are almost a direct bolt in. No driveshaft mods were needed on my '66, so I would assume the same on a '65. You may benefit from the overdrive with the 3.55 gear if you do some highway driving. Used the stock 2 speed shifter and console, but it won't manually drop into 1st gear. I may modify the linkage a little if I find the bravery. The 200r4 swap can get a little expensive if you do it right though. Find a good used trans from a GN if you want it to shift good. Some of the Caddy, etc trannys shift at like 4500 at WOT! Search 200r4, lots of good treads on it. I have not done a turbo 350 swap, but the trans is the same length as the ST-300. Good luck! Brian
Yea, I wasn't sure if the 400 trans was the same bolt pattern as the power glide thats behind your 300 V 8. Never brought up the nailhead. I kow thats a different animal all together. I wanted to make sure the t400 can be married to the little 300 V8. So your good to go if you wanted to go with the t400. Which would be alot cheaper than the 200 4 speed. imo.
Any turbo 400 can be mated to the 300, as long as it has the BOP patterned bellhousing.:grin: If you are looking to keep switch pitch feature, try 65-67 Oldsmobiles (not Toronado) or 67 Buicks. Cadillacs during 65-67 used switch pitch, but was a different bell.:spank: Oh, and BTW, you have a ST300 and not a Powerglide. The only similar thing about the two is that they are two speed autos. That is it. Powerglides never had switch pitch, and they are very dissimilar both inside and out. Also (aluminum) Powerglides were only used in Chevy's and Canadian Pontiacs. So they only have the Chevy bell pattern.:blast:
either a th350 or the 200R4 TH350 a little less $, no od, pretty bulletproof and easy to install, no driveshaft mods. 200R4 lower 1st gear and has OD- could be great to tame the 3.55 gears.
I'm kinda leaning towards the 200R4. What years were they made and in which cars? I'm actually pretty pleased with the 355 rear gears as it is but having OD will help the fuel mileage a little on long cruises. I assume that going to a 200R4 would eliminate the switch pitch switches, or can (why?) the SP torque converter be used with the 200R4. Did I read correctly that they will bolt up to the 300 or do I have to look for one with a specific bolt pattern? If I have to find a wrecked GN, I'm gonna be looking for awhile. Any guesses what these trannys go for from a local wrecking yard? Thanks again. Greg
My two cents ...I did the turbo 350 behind my 462 in my 65 as they are a dime a dozen , converters are cheap etc...it was an extremely simple swap, existing driveshaft works, linkages as others have said here ...200 has a better first gear and obviously the overdrive would be great but they are usually more expensive with the 3:55 gear you may want the 200 if you want to keep your 70 mph cruise rpms down...... J
Greg, do a search on here for 200r4 codes to look for. Basically the '85-87 turbo Regal, 442 and Monte Carlo SS are the ones to look for. All 200r4 have a dual pattern bellhousing and will bolt up to your 300. I found mine on the turbobuicks.com forum from a guy in WA that was parting out a wreck. $500 is about the going rate for a good core. It should have the BRF tag on the passenger side of the trans. Plenty of them kicking around for sale. Most of them seem to come from the rust belt where cars are getting parted out. Brian
from what i read the tranny works fine, except the leaks. i would use that tranny and find another trans shop. jim
I already tried that and it still leaks. The ST300 is known for leaky seals when they sit like mine over winter. The more I drive it, the seals swell up and almost stop leaking by the end of summer. I'm just tired of the mess which is why I'm considering the change.
Brian, Thanks I'll do a search. I didn't know before what to search on. Your help is appreciated. Greg
I would do the 2004R without thinking twice. Lower 1st gear and overdrive. The car will take off quicker and smoother and cruse at 70mph and only spin about 2200 rpm.(depending on tire size) ... Added bonus of better gas mileage...Best of both worlds You can use a toggle switch to lock the convertor or get a kit from TCI or BM to lock it automatic.
The 84 and 85 TR/GN's used a BQ coded trans, very close to the BRF 86/7's...Another option for you, and maybe a little cheaper than the BRF, although there are less of them out there...
Do some research at your local library. The January 2000 HOT ROD edition has a step by step swap of an ST300 for the 200R4. The title of the article is Over and Under, Installing a 200r4 in a two speed Buick. The only thing that had to be modified was moving the location of the trans crossmember. If you do go with a 200R4, make sure you get the TV cable set right the first time. Any one selling a 200R4 from a Grand National is going to charge you a premium for it, some research will find you one almost as good for half the price. Check www.shiftworks.com for modified shifters and quadrants that incorporate the original look with the later shift patterns. Ed
