454 flywheel question

[big83chevy4x4]

last week i bought a 99-00ish vortec 454 (gm test motor, has some not so 454 items on it, more like 496 stuff on it.) ive been looking for a flywheel but i can't figure out what fits. some web sites say all 454 flywheels are the same, some say up to 90, then 91 on are the same, some say up to 90, 91-95, and 96 on.

GM sells a flywheel for this for around $100, but it says 11" pressure plate pattern. i want to put a 12" clutch on it. if my local dealer had one in stock, id just take a measurement to see if a 12" clutch will fit. but they don't and if i order it, im stuck with it.

anyone know if it will fit or know of what flywheel that will fit the new 454 and a 12" clutch?

 

[dyeager535]

I hope someone will post up about the clutch size. I had always heard there were only two sizes, 11 and 12", but then found out that one is something like 10.4" or so.

It MIGHT be that the GM piece is 11.4 or something, and that's what everyone calls a 12"?

Ring gear count will tell you if it's a big or little flywheel, 168 tooth is big, 15x is small. Unsure if the tooth count changed later on.

 

[big83chevy4x4]

the tooth count is still the same, 168 and 153 on the new stuff.

i know they have 10.5" 11" and 12" clutches. the clutch i had on my 350 was a 12", measured 12" exactly on the tape. my dads k5 had a 11" clutch in it when we replaced it.

here is the flywheel im looking at
http://store.summitracing.com/partd...864926+4294840133+4294889123+115&autoview=sku

 

[JEBSR]

This is what I found. I thought the only differance was whether it was a 1 piece or two piece rear main, but maybe not. I see three differant types and they seam to be interchangible only in between the specific year models.

http://www.coloradok5.com/forums/archive/index.php/t-123526.html

http://store.summitracing.com/partdetail.asp?part=HAY%2D20%2D330&view=32&N=700+115&orig=1

http://store.summitracing.com/partdetail.asp?part=RAM%2D2532&view=32&N=700+115&orig=1

http://store.summitracing.com/partdetail.asp?part=MCL%2D460130%2D4A&view=32&N=700+115&orig=1