Joe Lucia-Powerglide Converter Pan #3933089

[Andy #28359]

Joe,

In an earlier post, you mentioned that a 1969-era replacement Powerglide converter pan is still available from GM (#3933089). Do you know if it will clear a 168 tooth flexplate? Is the replacement made of steel, or plastic that eventually cracks? This question is not for my Corvette but my '68 Chevelle which now has a 168 tooth flexplate (& later smallblock) with the 'Glide. The original steel pan hits the flexplate. Was '68 the last year with the smaller 153 tooth flexplate and the older starter? Thanks...

[Joe L.]

Re: Joe Lucia-Powerglide Converter Pan #3933089

Andy-----

No, the GM #3933089 underpan is for use with Powerglides utilizing a 153 tooth flexplate. It will not work with a Powerglide utilizing a 168 tooth flexplate. Most Powerglides utilized on Chevrolet cars from 1962-1969 utilized the 153 tooth flexplate. The exceptions, which used 168 tooth flexplates, were:

1967-69 models with 350 cid engines and Powerglide;

1962-68 models with 396, 409, and 427 engines with Powerglide;

Other applications, such as yours, could be converted from a 153 tooth flexplate to a 168 flexplate. After 1969, many small blocks equipped with Powerglide used 168 tooth flexplates. However, after 1969 Powerglides were a "dying breed". I believe that the last one was used in a Chevrolet car in 1973.

Applications using Powerglide with 168 tooth flexplates require underpan GM #3831527. This piece was GM discontinued in 1985. It's a LOT moree difficult to locate in used form than the underpans used for 153 tooth applications since Powerglides utilizing 168 toothflexplates were relatively rare. You'd have to get real lucky to find one of these in a bone yard. Your best bet for a donor will be 1970-73 Chevrolets with Powerglide transmissions. There may still be a few of those around. Even 71-73 six cylinder applications with Powerglide will do for a donor, if you can find one.

As far as I know, the GM #3933089 cover is a stamped steel piece, but it won't be of any use to you anyway. I believe that the 3831527 was a stamped steel piece, too, but I'm not certain of that.

Chevrolets with Powerglide and 153 tooth flywheels utilized a starter with an aluminum nose with "1 long and 1 short" starter bolts. Chevrolets with Powerglide and 168 tooth flywheels used starters with cast iron noses and 2 equal-length, "long" starter bolts.

[Verne Frantz]

Yes, 3831527 is steel *NM*

[Andy #28359]

Thank You for all the good info, Joe *NM*

[Chuck Swenson]

Re: Joe Lucia-Powerglide Converter Pan #3933089

I just looked at mine in box and it's a 168. Looks like I got the wrong one. Anyone know the part num for a GM 153 flexplate?

Thanks, Chuck
(66 327)

[Joe L.]

Re: Joe Lucia-Powerglide Converter Pan #3933089

Chuck-----

The GM part number for the flexplate for your application was GM #3789821. Unfortunately, it's GM-discontinued. What part number do you currently have?

[Chuck Swenson]

Re: Joe Lucia-Powerglide Converter Pan #3933089

Aftermarket for OE# 340236. Just looked it up here: http://www.bulkparts.com/MM007.ASP?pageno=1084

Looks like only 68 and up.

I didn't see the 66 listed.
Thanks, Chuck

[Joe L.]

Re: Joe Lucia-Powerglide Converter Pan #3933089

Chuck-----

I think that it's 340296. This flexplate is not correct for your application. However, I think that there are correct flexplates available in the aftermarket for your application even if they're not available from this outfit. Just use the number I provided in my previous post for cross-reference purposes.