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Discussion Starter · #1 ·
After spending thousands and thousands on an all new or rebuilt drive train, I'm trying to find the source of a vibration starting around 1800 rpms on a fresh 327 hooked to a T400. It does it rolling or parked. My exhaust is scarfed together and hard strapped to the frame and only goes half way back (getting new exhaust tomorrow). I was originally hoping that was the cause of it, but I'm having my doubts. I'm thinking that after spending the dough on everything except replacing my 40 year old flexplate,that may be the cause. ...My questions are what is the need for a thicker flexplate?...and what is the need for a flexplate spacer? I've schooled myself on types of plates, internal, external, all early small blocks except the 400 etc. but I've found no info on thickness and spacers. Thanks, Jim
 

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Thicker flexplates are used in high hp applications but in your case just normal plate will do. Spacers are for getting the right clearance between converter and flexplate, there needs to be clearance before converter is bolted otherwise the oil pump in transmission will go bad in a hurry.
I don't know if a flexplate can make such a drastic vibration though.
 

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Thicker flexplates are used in high hp applications but in your case just normal plate will do. Spacers are for getting the right clearance between converter and flexplate, there needs to be clearance before converter is bolted otherwise the oil pump in transmission will go bad in a hurry.
I don't know if a flexplate can make such a drastic vibration though.
What should be the gap between the flex plate and the converter be ?
 

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IMO, not a critical dimension as long as you actually have to move the converter forward to bolt it to the flex plate when the engine/bell housing are bolted together. For me, 1/8" or so is the sweet spot. Anything more than about 1/4" and you're taking away from front pump engagement.
 

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Discussion Starter · #6 ·
Well the vibration is'nt all that drastic, but you definitely notice it. Sometimes it's there loaded, sometimes unloaded. For sure seems like it's in the engine rotating assembly. I stopped by my trans shop and he said I could try rotating the converter by a 3rd. I read that somewhere else as well. If I end up trying a new plate, would there be any problem using a thicker one anyway?
 
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