I can't seem to find anything about there ever having been Super Duty 4 style cranks to fit the FWD flywheel flange. Every beefy crank I find, be it Industrial 3.0, Mercruiser IO 120/140, aftermarket, Super Duty, etc seems to be set up for the SBC bellhousing pattern blocks and takes SBC pattern flywheel. I have a 1977 style beefy crank in my basement, a good 45 pounder that has more than 2 counterweights on it but there's no obvious way to adapt it to a regular VIN R block.

Turbo Super Duty guy, MRossum, anybody?

Thanks
Kurt

[This message has been edited by KurtAKX (edited 03-08-2007).]

Don't have an answer, but I find the GM PN's for the crankshafts in the SD4 book.

Rough Forged PN 10027776
3.00" stroke PN 10027777
3.25" stroke PN 10027778

You might want this Super Duty 4 PDF. It's about 15MB and will take a while to download.

Right-Click the link and "Save Target As" to download and save to your computer.
http://calgaryfieros.com/DO...S/HotrodSD4guide.pdf

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3.4L S/C 87 GT www.fierosound.com
2002/2003/2004 World of Wheels Winner &
Multiple IASCA Stereo Award Winner

[This message has been edited by fierosound (edited 03-08-2007).]

Kansas Racing Products sells the SD4 cranks, they might be able to get you a FWD one. Or you could ask Scat, who makes them.

http://www.kansasracingproducts.com/products.html

http://www.scatcrankshafts.com/

From KRP:

quote The racer can order a crankshaft drilled with the Pontiac pattern or small block Chevrolet pattern to accept either flywheel. It is also possible to put the starter on either side of the engine block to accomodate the request of the racer.

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1984 Fiero SE

I had a 3.0 Mercuriser crank modified to fit the 2.5 front wheel drive (VIN # R) block. The machine work cost me $150. The crank I have originally had the large hub, one piece rear main seal and the SBC flywheel bolt pattern. The machinist turned down the hub and redrilled the flywheel pattern to the FWD 2.5 pattern. I have yet to assemble this motor and I am still working out the rod and piston combo. One thing to watch out for is the SBC rods will not fit this crank: because the 3.0 Marine motor rod width on the big end is around 1.038 while the SBC rod width is around 0.947 I believe. So you have to use the 3.0 rods which are 5.7 inches in length this should work with a 327 Chevy piston. With a .030 overboar and the 3 5/8 stroke this combo should produce around 184 C.I.

I just bought a 1 piece rear main crank today- does anyone have pictures of the way they modded the 1 piece cranks to fit the block. It seems that when you turn the crank down at the rear main seal area to match the FWD block, you are left with an interrupted surface because the bolt holes from the original crank pattern will poke through.

Are people plugging the cranks and then re-drilling?

Hey Kurt I have 151 racer's (I believe) modded 3.0 crank. When I get a chance I can take it out of the box and send you some pics when I get a chance.

The original Pontiac SD cranks are indeed set up for the R blocks and Duke flywheel. These have become somewhat hard to find, but are still out there.



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My Web page | The Turbo Super Duty Build.
You know that little voice that says it can't be done? I duct-taped its mouth shut and pushed it down a flight of stairs. (Leader of the Insurgency)

[This message has been edited by FastIndyFiero (edited 09-10-2008).]

Is this for the 1 piece SBC rear main seal?

Have SPEC cut you an aluminum flywheel with the 1 piece rear main flange pattern in it...