360 Flex Plate

[4mulaSvaliant]

Hey all. I have been trying to find out whether or not the stock flex plate on a 360 is the same as the stock 318 flex plate.
Story is:
About 10 years ago when I put my 360 together I built it on a High School budget. I did well really, but I think I put a 318 torque converter on it. It has a bad vibration through out the rpm range.
Now after many years of sitting (was in navy) and the fact that someone attempted to steal it when it had very little trans fluid in it. I think the bands are burned up. So I bought another trans just to get away from the drag strip/ street abused tranny.
I am going to buy the correct torque converter here in the next few weeks.

But I am wondering is the crank shaft bolt pattern the same between the 318 and the 360 on the flex plates?
Also, if it is not the same, then is it even possible to have bolted a 318 torque converter up to the 360 flex plate?
Yes I am aware I can just pull the inspection cover and check I just havent had time! lol
I am really just trying to see if I may have to but a flex plate aswell.
thx all.
Keep the A-Bodies alive!!!!!!!!!!

 

[stupidasso]

so I just matched up my 318 flex, and the holes lined up, however if you don't have the externally balanced torque converter, you'll have to get a balanced flex plate. I just got one from summit for 70 bucks.

 

[GoodysGotaCuda]

Alrighty here we go lol

a stock 318 or 360 flexplate will bolt right on to each other. Stock 360 goes on a 318 and vise versa. That vibration you had was because you put a converter for a internally balanced motor onto a externally balanced motor. Which, talking about factory balancers, is a no-no. The factory 360 converters have counterweights on them to balance the motor.

However, you can take that same 318 converter and bolt it onto a 360 with no problems if you run the proper flexplate that is counterweighted itself to balance the motor where the factory 360 converter would go. Forged crank 318/340 would take a neutral balance converter (no weights). Stick that on a 360 with a factory flexplate and you'll get that vibration you had. Stick it on that 360 with the b&m 360 flexplate and she'll run like a champ.

Hope that makes sense

 

[krabysniper]

Not to mention the front harmonic balancer is likewise balanced for a 360, and is not interchangable between 318/340 and the 360. I would get the B&M flex plate for the 360 as it will allow you to run any nuetral balance converter and you won't have to worry about trying to balance a converter everytime you need or want to change it. I did.

 

[dazedduster]

I just used the b&m flax plate and a higher stall converer on my 360, works great,
$75 for the flex plate. i say get one