Powerglide to TH350 swap in 67 Camaro

Hi all,
I've got a bone stock 67 Camaro that I restored a few years back that has a column shift Powerglide tranny. Rear gear is a 2.73 posi, rebuilt 327/4bbl, stock block/heads with the Duntov cam. It's just a
driver, not a race car by any stretch and it runs great once you get it moving. The problem is that off the line it is SO SLOW, so I'm going to make some changes this winter while the snow is flying.
Taking it to my buddy who rebuilt a TH-350 for me, he finds out that everything wasn't going to line up as we had expected it to. The shifter linkage already doesn't really work right because it hits the header when you go into park. So I was going to convert to a floor shifter w/ cable setup. However, it turns out that the 6" shaft TH350 is too short compared to the PG and the 9" shaft is too long. He had both TH350's there and measured and the PG measured somewhere in between those 2??? Does that make sense to anyone? I've definitely got the stock PG in there now, so it's not like it's some strange custom deal or anything. From the many articles and web sites that I've read on this swap, it seems as if it's completely straightforward with nothing special to do other than convert from the linkage to the cable for the kickdown, then whatever you have to do to the shift linkage or cable. If anyone has done this conversion or knows what the problem could be on the measurements, that would be greatly appreciated.
Thanks, Scott
'67 Camaro 327/275 '94 Suburban 350 '01 Suburban 496
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The TH350 cars had a different steering column, with a different shifter linkage arm. They had both a different drive shaft and a different transmission crossmember.
The good news is all this stuff can be found at swap meets, or thru restoration parts suppliers. A good start would be to call Year One. They probably have the parts in stock.
Charles
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On 19 Dec 2003 16:30:10 -0800, snipped-for-privacy@stratos.net (Doomie) wrote:

I did the swap on my old 68' and it was as strait foward as they come. The TH-350 I used (6" tailshaft) bolted right up at the same point as the PG that was in it. I didn't change the driveshaft since it bolted right in with the correct front yoke for the transmission. The only change I made was the cable and mount, I had to use one from a 3 speed tranny. Of course I had the floor shifter to start with so that kept things more simple. The original shifter even worked with the 3 speed. Good luck with your swap.
...Ron -- 68' RS Camaro 88' Formula Bird
http://www.frontiernet.net/~rscamero
Some are wise and some are otherwise
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I did find some dimensions on TCI's website, here's the link for other's to check out:
http://www.tciauto.com/tech_info/trans_dims.htm
Interesting thing was that the according to it, there's a short and long shaft version of the PG. Short is 25 23/64 and long is 27 9/16. Now if you look at the TH350 measurements, it shows 27 11/16 for the 6" shaft and 30 11/16 for the 9". So to have a PG somewhere in the middle of those 2 really doesn't make any sense at all. I would tend to think that the long shaft PG is what's in there now, with the 6" TH350 only 1/8" off, which would work fine with the existing driveshaft. I'll have to go take some measurements myself and see what I have in there now, maybe the measurements my buddy did just weren't right? Knowing that somebody else has done this same swap on basically the same car makes me feel better anyway. The kickdown and gear shift set-up doesn't bother me at all, that can be figured out fairly easily. But if it all just bolts in with the same crossmember and same driveshaft, that will make life much easier and much cheaper!
How about the flexplate, is that different between the PG and 350?
Thanks, Scott
'67 Camaro 327/275 '94 Suburban 350 '01 Suburban 496
(Doomie) wrote:

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On 20 Dec 2003 11:25:18 -0800, snipped-for-privacy@stratos.net (Doomie) wrote:

I didn't replace the flexplate that I can recall. The torque converter just has to be one that was made for whichever trans you are putting in. The bolting method to the flexplate is still 3 bolts @ 120º apart. I know that when you change from the PG to a TH-350, you need to use a short shaft TH as that is what will fit without having to move the crossmember and shorten the driveshaft. On a side note a T-10 or Muncie 4 speed also uses the same crossmember and driveshaft. My current 68' RS had a PG and now has a T-10 using the same drivshaft and crossmember. Just make sure that the front yoke is the correct one.
...Ron -- 68' RS Camaro 88' Formula Bird
http://www.frontiernet.net/~rscamero
Some are wise and some are otherwise
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OK, I went out in the driveway and measured the old PG best I could and the measurements came out to about what the TCI chart says it should. The TH350 that was to be swapped also measured out correctly??? Not sure what was happening before, but from MY measurements, it appears this is as straightforward a swap as it should be. I'll have to get the Camaro down to his shop where he can put it up on the lift and get a more exact measurement, but from what I did, it looks like it should slide right in there with minimal effort.
Any thoughts on torque converters? I'm running a hydraulic version of the old Corvette 327/350 cam, totally stock and freshly rebuilt motor otherwise, with sad 2.73 posi gears. But it cruises nice on the highway! TCI suggested a 2,200 stall converter, which seems about right to me. Just wondering what other people were running with a similar setup and what they thought about it. I had been going back and forth between a 2000 and 2400 stall converter from B&M prior to speaking with TCI.
Thanks, Scott

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Powerglide torque converters tend to be a higher stall speed than that of the three speed Hydramatics. In fact they were once known as the poor mans high stall speed converter. You might give that a try. It should slide right into the front of your TH350. - Gary

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The slow off the line prob. is not the trans, its the 2.73 rear end.You need to go to a 4.11 or higher to get a jump off the line , but you will lose some top end sped. The ERN
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I had thought about swapping gears, but I do a lot of highway cruising with this car, and really like the lower RPM's with the 2.73's going 70 MPH for extended amounts of time. The TH350 swap keeping the 2.73 gears would have the same first gear effect as putting a 3.91 gear in there right now with the Powerglide. That's why I figure the TH350 gives me the best of both worlds, much better off the line with the same nice highway habits that I've got with it now. I should have mentioned that it's a drag race car by any stretch, that's not my intent for it. I just want a nice cruiser to have fun with, but I want to also get up and go with a little more attitude than it's got now. 700R4 with numerically higher gears would probably the ultimate set-up, but the 350 swap seems to be a lot easier and more reliable, not to mention the cheapest!!!

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