73 340 w/cast crank...Auto to 4SP Question

[ShelbyDogg]

So I picked up a rebuilt '73 340 and 727 from a guy going big block. I hear this is the only year for the cast crank 340 and noticed that the torque converter has the large balance weight to complete the external balance.  Here's the problem: I want to put a 4-speed on it and not use the converter.  The rumor is that all 73 340 4speed cars came with internally balanced forged cranks.  Is this true? I found a guy to sell me a '73 340 flywheel, but he took pics and I don't see any added weight, so the rumor may be true.    So.....  at the machine shop, should I have them weld this weight to the flywheel to offset the flywheel the same weight OR should I have them lighten the other end by drilling holes into it.  Taking the engine apart for another rebalance is out of the question.  I found a rolling 72 340 4SP Cuda that needs an answer soon.

Rob

[Mopar73340]

73 340's had EXTERNALLY balanced CAST cranks. The flywheel should be balanced along with the rest of the bottom of the engine. The flywheel will not have weights added to it but it will have holes drilled to remove weight in the proper location. I just converted my 73 the same way although I had the engine internally balanced without the flywheel because I didn't have one 15-20 years ago when the machine work was done. I went this route because I was not sure where the engine would end up at the time so I would be able to use it with non balanced flywheels or torque converters.  BTW the engine came out of an auto car and is now in front of a Keisler 5-spd.

[ShelbyDogg]

Rebalancing the crank is not an option for me.

[moparnut]

Correct me if I am wrong but you need to make sure it has a manual tranny crank for the pilot hole,not sure if in 73 they were all with this feature but some earlier one's were not

[Robb]

Im pretty sure that Kiesler Install Kit supplied bushing.  Takes care of you on the crank "issue". 

[moparnut]

Im pretty sure that Kiesler Install Kit supplied bushing.  Takes care of you on the crank "issue". 

To my understanding its not the tranny but the crank,it doesnt matter if you have the bushing if it donest fit into the crank

[Mopar73340]

To my understanding its not the tranny but the crank,it doesnt matter if you have the bushing if it donest fit into the crank

As stated above, I just installed a manual trans behind a 73 cast crank, all you need is the pilot bushing. You should be able to get a properly balanced flywheel although the best way is to balance as a complete unit.

[Robb]

To my understanding its not the tranny but the crank,it doesnt matter if you have the bushing if it donest fit into the crank

and Kiesler supplies you a bushing that fits to the crank, even an automatic tranny one.

[Mopar73340]

 

[ShelbyDogg]

Okay, so I already know about how to mate a 4speed to a crank.  Drilled, not drilled, drilled but not the right size, roller bearing in the hole, external bearing in the flange, cut the tip, don't cut the tip, drill the hole, etc.   So back to the original question: does anybody sell a flywheel externally balanced for a '73 cast crank 340? Has anyone here ever welded the offset weight from a torque converter to a flywheel and had success? I find flywheels for $20 at swap meets and I worry about it coming apart if I have it lightened too much on one side with a bunch of drilled holes.   

[Robb]

I had to buy an externally balanced flywheel to fit my 77 440 cast crank and it was NOT easy to find.

I had to call around to a few flywheel manufactures.   Kiesler was able to get one for me for about the same price as anyone.



                                                                             steel         aluminum    teeth  diam
1972-73  340 ENG. SM FLY W/CB W/CAST 6 BOLT CRK   464102-7A  564102-7A   130 13.195

http://www.mcleodind.com/cgi-bin/fccgi.exe?w3exec=w3ezmenudriver&menuvalue=38&currmenuid=WMM&src1=/catalog_htm/2003cat.htm&w3hostname=MCLEOD

Mcleod industries.  they arent the only ones though.  If you call Keisler, they have a supplier that happens to use the same stock numbers.


to drill the holes on a 0 balance one,  you dont go all the way through, you just go deep enough to remove some material in an exact location using templates.  The Machine shop doing the work should still measure the amount of material removed by doing a before and after weight.

http://www.moparaction.com/Tech/quest/internally.html 
this is for a 360, but its the same process.  out on the net somewhere is the 340 pattern diagram (Ive seen it) just gotta google

[57hemicuda]

The 318 used the same crank as a 340.You may just look for a later truck 318 flywheel.The only thing with that is it uses an 11 inch clutch and I don't think it will fit under a small bellhousing.You may be able to use a truck bellhousing it is dual pattern for the big transmission and the car type,but I don't know about the clutch linkage

[ShelbyDogg]

Thank for the input, I know a 318 steel crank will fit, but the engine has been rebuilt already and isn't going to come apart till I put at leat 50,000 miles on it.  At that rate with my other cars, will take 50,000 years for me to rack up.

Robb,  Thanks for the answer that I was looking for. There are alot of smart people here with smart answers. Yours was just the smartest answer for this question.  Thanks

Rob

[matt63]

If you find a neutral balanced flywheel and the dimensions and specs for where the balance holes have to be drilled you should be set.  It will be a "factory" balance only.  I believe that Mopar Action had the drawing on line for the 360 flywheel balance.  I believe that the 340 and 360 had a different balance spec.  http://www.moparaction.com/Tech/