Soooo.... I've searched and found no answer for my particular question. So here we go. My 1985 Iroc has the manual trans with the flywheel with no weight on it, so it is meant for a internal balance SBC. Now, since my little 305 decided to put a connecting rod through the block, it will be getting replaced with a ZZ4 Crate Engine which of course the wads at chevy only sell with a flexplate and not a flywheel.

So, quoted 360 friggin dollars for a flywheel which is externally balanced is pretty damn ridiculous here in good ol Canada. So has anyone ever had a internal balance engine flywheel machined or modified in anyway to make it externally balanced for this new crate engine. Because with only 19,000km on the car since 1985 it is still like brand new, not even a ridge and I feel it is a waste to toss it.

Any insight is greatly appreciated, as my engine is still en route to my house thanks to canadas slow postal services I have some time.

Thank you.

 

The 85 wheel will not fit the 1-pc rear main seal crank in the ZZ4.

Forget "internal" and "external" balance. Both motors are internally balanced; the only difference is, the rearmost bit of INTERNAL balance weight on a 1-pc RMS motor, is mounted on the flywheel instead of the crank. That DOES NOT make it "external" balance.

Forget that terminology though. The word you want, is "stock". Real eeeeezy. It's all you need to know.

Get the STOCK flywheel for a 86 - 92 Camaro/Firebird V8. You'll find there are 2; a 22 lb one was used in the granny grocery-cart cars with LG4 and L03, and a 16 lb one was used in the performance cars with LB9. More likely you'll want the latter. Doesn't have to come from the GM store; you can get a junk one, a replacement one at the part store, etc.

 

What sofa said.

No you can'tr machine/convert a 2 rms flywheel to a 1 rms flywheel

You just need a flywheel for a 1pc rear main seal SBC " internally balanced". Stock or aftermarket for the 1986 up engines. $93 at auto zone http://www.autozone.com/drivetrain/f...5709_233476_0/

The 400 small block was the only factory engine to be externally balanced.

Oh you do need to check what tooth count you have now so your starter will work. 153 or 168 tooth.
The one I linked to above is 153 tooth.

$89 http://www.summitracing.com/parts/zz...make/chevrolet
$93 http://www.summitracing.com/parts/zz...make/chevrolet

 

IIRC; isn't the 85 a 1-piece RMS block that had perimeter bolt heads.... ??

<edit> My Mistake; that was 86 !

I just converted an 80K mile 86 IROC from auto-to-stick last month. Here's a 1-piece RMS Autozone Flywheel compared to stock (heavy) Flywheel from 86 IROC. ( cost about $95)






168 tooth flywheel will NOT fit inside the T5 bell,....... get a 153 tooth !!