318 converter and bolts with 5.9 magnum flexplate

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540demon

540demon

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the converter uses 5/16 bolts.
the holes in the 5.9 magnum flexplate are .050 larger than the ol stock 318 flexplate's hole.
is this gonna be a problem?
the converter snout is lined up by the crank...correct?
will the extra .050 clearance be like a sloppy u joint,and be a problem upon acceleration and decceleration...or will it be ok once tightened?

ive found that others have hogged out the one flexplate hole (to compensate for the offset converter lug) and gotten away with it,but never heard any mention of the different bolt size.


im trying to use up the extra junk i got laying around. its a 1997 5.9 engine/flexplate,and a 1971 904 converter/trans.

thinking about slappin er together an see if it works...anybody been here before?
5/16 bolts in what seems to be 7/16 or maybe even metric holes?
 
You would just be better of going with a b&m external balanced flex plate made for the 904 or 727 its around $80 bucks at summit thats made to fit i burnt up a 727 running the wrong flexplate on my magnum motor

heres the link
http://www.summitracing.com/parts/bmm-10239
 
I know what you're talking about, and I ran mine like that up until I decided to swap transmissions. I just used red loctite on all the bolts and checked them frequently for the first couple thousand miles, but they never budged. I'd say you're good, but you might want to keep an eye on them just in case.
 
That's quite a bit of difference. Nearly 1/16"... If your running a fair amount of power and running it hard (racing) it might be an issue. You can do like UOP said and check them often and if you get lucky your good. If not your yanking the trans. back out to replace it. I guess it's your call.
 
downs8 said:
You would just be better of going with a b&m external balanced flex plate made for the 904 or 727 its around $80 bucks at summit thats made to fit i burnt up a 727 running the wrong flexplate on my magnum motor

heres the link
http://www.summitracing.com/parts/bmm-10239
Click to expand...

that's not the correct flexplate for his 360. That's for a LA 360. 360 magnum's have a different ammount of imbalance. I looked on Summit's site and they don't even show a flexplate for a magnum engine with a 904. Just this one to mate it to a 727.

http://www.summitracing.com/parts/bmm-10242/overview/make/dodge
 
b&m quit making the 904 to magnum flexplate..
 
Yep, b&m quit making the correct flexplate
Mopars balance and template kit ( to weld on the converter)...doesn't come with a template (and is discontinued)
This is the only way to do it now....that doesn't involve a custom converter.
Glad it worked for uop...I'm goin for it!
Thanks for the input!
 
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