TH 350 for my '65

[Boogieman]

My P/G has started slipping. I've got a rebuildable TH350 in the shop. Does anyone know EXACTLY what's needed to make the change over? My trans shop will do the conversion if I get all the correct parts. (They can't tie-up a bay/lift for more than a few days). Chime in if you have a clue!

 

[Mikey1]

The shifter is different....so the whole thing is slightly highter. That makes the shifter come out highter into the cockpit which means that you need to craft something to cover the shifter (differences).

 

[WayneC]

Forget the TH350, it needs rebuilding, too. If you're going to the trouble & expense of a conversion rather than just rebuilding the Powerglide tranny, why not go with a 700R4 and get the advantage of overdrive?

These guys may be able to help you figure out what all you'll need (driveshaft, cooling provisions, TV cable, OD lockup wiring, mechanical speedometer issues, converter & bellhousing, crossmember mount, shifter, etc)...

http://www.bowtieoverdrives.com/index.shtml

http://www.bowtieoverdrives.com/catalog/catalog_inc/viewitem.php?ITEMID=114

 

[Boogieman]

The main reason is that I already have a TH350. I don't want to add the cost of another transmission plus a rebuild too. This seems like a simple swap if I can just figure out the parts, like flex-plate, mount, torque converter etc. Rebuilding the P/G will be around $700. To rebuild the TH350 is $450. Seems like i'd be $250 towards the conversion with the TH.

 

[bossvette]

Its been a longggggg time since I've done anything with a powerglide/th350, but my foggy memory tells me it was a direct swap with the exception of the shift pattern and there are ways around that.

newer year shifter, don't use low, file another detent in yours etc.

 

[Ron Miller]

I ran a turbo 350 in my 62 back when I bracket raced , converters are
not the same ,get a new flex-plate might save you $ not to pull the
the new trans to replace the old one . $700 to rebuild the P/G and
$400 for the 350 does not sound right , would check with some of the
local racers for someone that knows how to fix your trans and
improve it . If you could get a reasonable $$$ rebuild I would stay
with the P/g .

I'm in agreement with the above.

 

[Boogieman]

Re: Th350/PG

The trans guy is a long-time friend and has rebuilt/ worked on my project cars for years. PG parts are semi-expensive due to small numbers left in street use. The TH350 rebuild is cheap due to so many around. TH350's can be rebuilt around here for $500-$700 total. What I'm looking for is the right flex plate/starter ring, torque converter, mounts, vacuum modulator, kick-down, etc. The stock shifter can be re-used . Cost isn't the issue, drivability is.

I was hoping someone here had done this before. If not, I'll do more checking and archive the info.

 

[midyear]

I have done several PG to T350 swaps in midyear vettes, it is an easy, very straight forward swap. Trans will bolt directly in place and can use the same mount, crossmember, trans lines, and driveshaft. Modulator line will require a small amount of modification, orig PG shifter will work, but you will need a shifting arm to mount to the trans as the powerglide arm is not one that just bolts on. By experimenting with the length of this arm you can make the shifter work all the gears, the indicator will just be slightly off. Flex plate and starter will work, just be sure your converter has the smaller GM bolt pattern on it, (I like to try and find an 11" converter) you will also need to fab up kick down cable brackets, not required to make the trans fuction, but without your WOT shift points will not be very performance oriented. As for the 700R4 trans, much beter trans with the advantage of having overdrive, I have had one in a 67 for 9 or so years, makes it a fantastic road car, but is much more difficult to install, requiring many more fabbed up parts. pop me an email if you need more specific info, happy to take a phone call as well.

Dennis

 

[mike weyman]

i have a fresh built glide with a new 2500 stall convertor.i went with a th350 instead ,as the 308 rear and the log first gear will suck for performance.
the glide is nearly bulletproof and can handle 600 hp. easily.
too bad you weren't in canada, i want 500$ cdn for the glide and convertor the convertor was 300 dollars and is still in the box.mike

 

[Boogieman]

Hats off to "midyear" and "mailmaninvette" for the info. Just what I was looking for. As to shift linkage, I've seen advertised a new shifter detent plate that allows use of the stock shifter and linkage. Can't seem to remember the company just now though. I want to keep the stock set-up for looks. Kind of a "sleeper". My '65 has the 3.36 rear end which is almost perfect for the street. Thanks again guys.