CRG Discussion Forum
Camaro Research Group Discussion => Mild Modifications => Topic started by: jpic on April 25, 2009, 04:04:07 PM
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I am swapping out my PG transmission on my '67 327, 210 hp, to a Muncie 4-speed. I bought a 621 (big block) bellhousing for this conversion. I believe I must buy a 11 inch flywheel and clutch set-up. My question is: there are different number of teeth flywheels out there, does it matter which one I buy? Also, I may eventually buy a small block crate engine for this car.
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With the 621 bellhousing, you have the option of using either a 12-3/4" 153-tooth flywheel or a 14" 168-tooth flywheel, and a 10.5" or 11" clutch (depending on how the flywheel is drilled). The 153- and 168-tooth flywheels take different starters.
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How can I tell what starter I have so I can get the right flywheel?
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How can I tell what starter I have so I can get the right flywheel?
153 tooth -- starter mounting bolts are inline
168 tooth -- starter mounting bolts are off set (staggered)
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Here's a tip that has always worked for me--when you put everything together for the first time, take the solenoid off of the starter, bolt the starter up, and pull the Bendix into engagement with the flywheel teeth. You should just be able to slide a thick paper clip between the high point of the Bendix tooth and the low point between the flywheel teeth. This will tell you if it needs shims, or if you have the wrong starter and it engages too deeply. Beware, there are 2 different versions of the 'straight-pattern' and 'staggered pattern' starters. Some starters had cast-iron noses and they will engage diffferently from the aluminum-nosed ones.
I've found that as a rule, if you buy an aftermarket 168-tooth flywheel it'll be already drilled for 10-1/2" and 11" pressure plate patterns, and the standard 168-tooth starter will work fine. If you go the original GM route, you could run into problems.
Also, be sure you know the spline of the input shaft of the Muncie--if it's an M-22 it'll have a different spline than an M-20 or M-21 and you'll run into clutch disc compatibility. Also, different pressure plates use different-length throwout bearings--flat diaphragm, cone diaphragm, 3-finger type, Borg & Beck...
I don't mean to make it sound so complicated--but this is stuff you could run into. For my 2 cents, I'd call Summit or Jeg's and talk them. They know what they sell and what works with what, and they can set you up with a complete package right out of the gate.
Good luck!
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You can't mix and match the factory stuff much. 621 bellhousings will require the starter for the large flywheel AND the larger flywheel. The flywheel can be drilled with both clutch patterns and either large or small clutch will work but the smaller flywheel will not work inside a 621. The flywheel does physicaly fit inside the bellhousing but the starter nose cone that is required to drive the smaller flywheel will not bolt up.
-Mark.
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Thanks all, for the information. I will be calling on one of the Camaro parts outfits to make sure I get it right.
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Hey jpic....
Just curious how your project is coming....I did this same swap last fall, and it is well worth the cost and hassles. Makes for a whole new experience and fun driving.
Have you determined which rear end ratio your car has? The standard rear end ratio supplied w/ most automatics will be a bit "tall" for a stick shift trans.
By the way, where did you find the Muncie, and what shifter will you be using?
Good luck....!
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I am slowly getting the job done. Last week I dropped the PG out, of course the crossmember hung it up, but when it did come free, it fell off my jack and started emptying its fluid on my floor. Today I am spending a few hours on getting the AT bracket off the frame, of course, the nut like fasteners on the inside of the frame are spinning around and around.
My rear end I am sure is quite tall, and that will be dealt with all in good time and money. I found my Muncie on Craigslist last spring and it came with a Hurst competition plus shifter.
I am doing the job for the fun of it and saving a pile of money I would think. Oh, and today I just ordered my Zoom clutch set-up. I am sourcing a lot of this stuff from NAPA. It's cheaper then most of the Camaro vendors, and generally, there is no shipping costs.
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DZAuto has pic's of all this if you want to hunt him up over on I think Team Chevelle.
He also has pic's of the CHEAP big-hole P/U bell housing too and tell's how to use it to save some MONEY!
pdq67