Brandon50394

i had to buy a flexplate for my 73 corvette 350 its a 168 tooth flywheel
on the package that i got it says its for a 454 does it make a difference?

Doug1

won't work, the end of the crankshaft is different. bolt pattern too I believe

CA-Legal-Vette

I'd have to check the bolt pattern but it won't work because the 454 is externally balanced and the 350 is internally balanced. There is a counterweight welded to the 454 flex plate.

Doug1

well then he could grind the weight off if that were the only difference. but the center of the crankshaft is larger then on the 350, even if bolt pattern is the same, which I don't think it is. center is different

tfi racing

Up to 1986 or so the sbc and bbc crank flanges are the same,the only difference is the imbalance weight added for the 400 or 454.You could knock the weight off,but why bother SBC flexplates are dirt cheap.

Doug1

hmmm. I certainly could have had flexplate that was improperly labeled as "350", maybe it was for a 305 or something? but the flange was definitely smaller then the 400 crank used on my 383

Doug1

I just measured the size of the hole on the flexplate that I had laying around with the label "350" on it. 2.06 inches with my micrometer. pretty sure I read it correctly. what size is flange on those crankshafts?

bashcraft

I don't know what flexplate you have, Buick, Olds?? All chevy's of that era could physically be interchanged with the only difference being the counterweight for 400's and 454's.

jnb5101

what's the diameter of the plate you need? 10 1/2 " or 11"? the bbc need the 11" which has 168 teeth, the sbc needs the 10 1/2 " that has 153 teeth. check the bolt pattern on the converter. the pitch is the same on both, the difference is the circumference. i just changed a sbc muncie to a th400 that was from a bbc. the 10 1/2" flex that i bought wouldn't bolt to the bbc converter. i used the original flex plate that bolted to the sbc without a problem. if you want a 10 1/2" flex plate , i've got a brand new one for sale!