Hi all i have a 58 biscayne sedan delivery fitted with a 327 v8 and aluminium powerglide, I want to fit a th350 transmission and need some help namely I know the drive shaft length is an issue on the original cast powerglide but as mine has been retro fitted with a later aluminium unit will I still need a modded driveshaft ? or has mine been modded already ? also I assume the yoke has been changed for the correct one for a th350/ aluminium powerglide. Can anyone offer any advice please regards Charlie
Charlie: Here's my thinking on this. I swapped a p-glide for a 350th in a '65 impala a few years ago. The trans mount is same location, yoke /spline was the same, driveshaft length didn't change. Bolt in other than changing flexplate. I think your experience should be the same if your using an older trans. There will be others who can correct or confirm my thinking. tim
Cheers for the reply Tim i'm hoping the driveshaft won't need altering as I am doing the changeover in my yard with no workshop facilities, so the easier the better.
Aah ok the powerglide I have is a 1968 and up model does anyone know if thats the same as a th350 ? cheers
Shifter hookup and kick down would be the only thing that may hang you up. I've never worked on a column shift swap. Length isn't exact but very close, output spline is the same. Get the glide out and set it next to the th350, you'll see if Trans lines, shifter location etc need small tweaks. Nothing major to hang you up.
Cool thanks for all the info I'm looking to go with a aftermarket shifter and kickdown so hopefully a pretty straightforward swap Once again thanks to all who replied Charlie Posted using the Full Custom H.A.M.B. App!
Yes but I don't have the th350 transmission yet it's getting delivered in 2-3 weeks, just thought I'd try to sort any possible problems before I got started
PG transmission either 28-5/16 or 25 -5/16 is what you have. Shortest TH 350 trans is 27-5/8 You will need modifications
It'll be an easy swap, you'll need to mess with the shifter linkage and the kickdown cable, the rest should be pretty straightforward.
It is an easy swap, I changed a Powerglide for a TH350 some years back. You have all the technical information you need, just remember to take you time and drain the transmission completely before taking it out of the car. Nothing is worse then having to clean up a mess because you were "in a hurry to get it done".
Cheers guys many thanks can we confirm wether the drive shaft needs modifying, I'm replacing a 68 and up aluminium powerglide with a short th350. Sorry to keep asking but some people I have spoken to say it will others say it won't. I'm just trying to know what to expect as getting a drive shaft modded over here takes about 6-8 weeks Cheers Posted using the Full Custom H.A.M.B. App!
you should expect the driveshaft to fit. But there are all kinds of things that may cause problems, which we can't forsee....since the transmission and driveshaft have apparently been changed already. For example, it's possible the Powerglide you have is not really from 1969, etc.
Crawl under there and measure what you have now. It's the only way to know for sure. Is that not possible ? Well you'll have one of 2 things happen. You have the Long PG to shortest 350 @ 27-5/8 and your drive shaft will have 3/4" less engagement or short. Or if you have the short PG to shortest 350 and then your drive shaft will be 2-5/16" too long.
Powerglides to fit the "X" frame cars (58-64/58-62 were cast iron,except the 62 327 cars got 25 inch aluminum Glides; All cast iron Glides could have been 28 inch cast iron Glides as I don't think there ever was a short cast iron Glide) would need to be 25 inch models, all the rest are 28 inches. There is a L-O-N-G Powerglide that was used in some trucks that is 32 or 36 inches long, and I have never seen one of those. If you have a short TH350 (6 inch extension housing)coming, and have a 28 inch long Glide, the drive shaft will not need to be modified. If you have a 25 inch long Glide, the driveshaft will need to be shortened 3 inches. If your Glide is in fact a 68 model, then it is a fine spline output shaft, and has the same splines as a TH350. Get the throttle pressure/kickdown bracket to fit whatever engine you have in the car (E-Bay has many of them). I went out to the garage/shop and measured my short shaft TH350 and the 28 inch Glide and there's only 1/4 to 1/2 inch difference just to make sure. I also have a 25 inch Glide, and a 9 inch extension housing TH350, and a TH400 short shaft. I think you'll be OK with everything you have. You did't say what shifter you had, but you may need to change detents if it's aftermarket; a stock column shifter, you'll just have to see. I am Butch/56sedandelivery.
Huge thanks guys really appreciate all your help and advice il let you know how it all goes. It is a bit of an unknown where it's all been changed/ modified before I got it. Posted using the Full Custom H.A.M.B. App!
Ok guys I've been out and measured the glide in my car and it's a 28" unit and definitely a 68 and up aluminium unit. So hopefully it should be a pretty painless conversion, I reckon I will have to go with an aftermarket shifter but that's fine. Any thoughts gratefully appreciated, and once more many thanks to everyone who commented, offered help and advised Charlie Posted using the Full Custom H.A.M.B. App!
The long ones were mainly offered in station wagons from my experience. The short TH350 and PG should be the same length.
Turned out as easy as people said driveshaft didn't need modifying, crossmember didn't need modding and used aftermarket shifter and lokar kickdown so basically a bolt in job
The Jalopy Journal
