Flywheel and Externaly Balanced Enigne

[Fuelie74]

I am getting ready to replace my flexplate with a flywheel for my 5 speed swap. I have a 1 piece rear main block. Several years ago I picked up a new flywheel at a swap meet for $10 the have the 1 piece rear main bolt pattern. Part number 14088671 N. I don't know what the flywheel is off of though, just that is has the right bolt pattern and is 153 teeth. How do I need to go about this swap as far as engine balance.

 

[Twin_Turbo]

Does it have a big balance pad like this one? (12 o clock pos) ?? This is a Mark IV BBC flywheel but the idea is the same.

Not sure if your part # is correct but if it actually reads 14088761, that is a 14" 168 89-up 350 HO, one-piece rear seal, ext. bal.
Here check this for reference:
http://www.vettemod.com/forum/showthread.php?p=49410

 

[Fuelie74]

It has a weight in the same position. I didn't get the number wrong but it isn't on that list.

 

[Twin_Turbo]

I may have the number wrong...hold on.....I'm an idiot, didn't read correctly...14088761 is a part number for a flexplate not a flywheel

Looks like 14088671 was originally used on the 3rd gen F bodies w/ T5, that would make it a 1 pc seal int. balance one. Your pics show an internal balance one also, it's missing the large balance pad.

 

[Fuelie74]

Well it doesn't have the same balance pad as the one in your picture but, it does have a raised section in the same place.
It looks very similar to GM p/n 14088650.

 

[Twin_Turbo]

Yes, but it has 3 small ones, evenly spaced around. The other one in my pic has one very large one and 2 small ones, the large one is also offset clockwise in respect to the other ones when you consider 3 spaced evenly over a circle. See what I mean? That big block is what makes it an external balance flywheel. Can't miss. Flexplates have a weight welded there.

You could add a bolt on balance plate between the flywheel and the crank.