Flexplate on Pontiac 400

[CoelacanthsKill]

I can't really get under my Buick and see if the poncho flexplate has holes for a 10-3/4 torque converter. I was given a used torque converter with the purchase of the car, but I know not to put an old converter of unknown condition on a newly rebuilt transmission. I bought a new converter and I seen the holes that mounted the old converter were farther out than what I bought, so I can only guess they're 11-1/4.

Assuming the stock flexplate is still on, does it have holes for both 10-3/4 and 11-1/4, or should I just buy a new one for safety reasons?

I found this flexplate that I believe fits a Pontiac 400, but I just need confirmation it will fit with my 75/76 block and 10-3/4" torque converter going on a th350. Do I need shims or anything else?

 

[MrSony]

http://www.gtoforum.com/f122/10-75-11-5-torque-converter-bolt-pattern-38884/

 

[MrSony]

Had a long winded "Do this, then do this" explanation, but said screw it and found a link. lol. There's no way to tell unless you look at it. No real need to buy one, unless the motor was out of balance. But if i remember right yours was rebuilt a while ago, so it should all be copacetic.

 

[CoelacanthsKill]

Problem is the car is on gravel under a carport and I dont have a floor jack on the property where its sitting, so its pretty hard to get under there. Ill try to see how far I get under in like 12 hours